Silicon Carbide (SiC) wafers are specialized materials employed in semiconductor technology, crafted from silicon carbide. This article explores the advent of silicon carbide (SiC) wafers and how it has opened up new possibilities in power electronics.

Silicon Carbide (SiC) Wafers: Revolutionizing Power Electronics and Beyond

Understanding circuit board components is essential. It's key to creating and fixing gadgets in our tech-filled world. In this article, we’ll explore popular circuit board components and various techniques to identify them.

Circuit Board Components Identification: A Comprehensive Guide

PCB with a green solder mask and high-density interconnects

A microvia connects layers in HDI substrates and PCBs, enabling high input/output density in advanced packages.  This article delves into the role and significance of microvias in modern electronics, exploring their impact on device miniaturization and functionality.

Microvias: Pioneering the Future of PCB Design and Electronics Miniaturization

Q: What is driving market growth for Wide Bandgap (WBG) devices?&nbsp;With gallium nitride (GaN), efficiency is the key driver which impacts everything else, resulting in less heat, smaller size and lower cost. The fundamental market drivers within the power field are efficiency and cost. Efficiency has been driven by regulatory requirements, but also by market requirements for power supplies to be smaller and lighter. Looking at cost, Power Integrations is finding is that for higher-end power supplies with a higher spec, GaN is the lowest cost approach because it saves heat sinking and the extra switches necessary for complex topologies.&nbsp;But optimizing the potential of GaN requires new system-level thinking. The old topologies that were invented to compensate for the challenges of using silicon are not required, because GaN is much closer to being an ideal switch. By that I mean that GaN devices switches very, very fast, they have a very low gate capacitance, and very low output capacitance COSS. But that brings with it a different set of design challenges. Power Integrations has found that the best way to work with GaN is to build a system around it. So we create sub-systems in GaN, such as our InnoSwitch™ flyback power supply ICs, our power factor correction HiperPFS-5™ parts and our LytSwitch-6™ LED drivers. We have brought to market GaN devices that benefit notebook adapters, cell phone adapters, small power supplies, LED lighting, etc, and there is much more to come.Power Integrations is following the same system-level strategy for silicon carbide, and we're seeing the same system-level benefits. When it comes to picking which WBG technology to use, the differentiation in our minds is voltage level: we're using silicon carbide in 1700 volt products which are targeting 800 volt automotive applications, but for 400 volt automotive applications, we think GaN is the ideal solution.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1708323818106-ezgif-2-d7c996fa21.jpg" style="width: 766px;" class="fr-fic fr-dib">Q: What are the trade-offs between using a wide bandgap semiconductor device and a traditional silicon-based device?It's a complicated answer, but I think that the enclosure size target is the determining factor. From the enclosure, the available heat budget - in order to fit a suitable power system into that enclosure - can be calculated. From this, designers can evaluate whether they are able to use silicon with a simple topology, &nbsp;or whether they need to use silicon with a complex topology &nbsp;or GaN with a simple topology. The benefit of GaN lies in its low cost of switching which means that it can be switched without having to use a resonant topology…which is how you achieve similar results with silicon. The moment you go with resonant (LLC), you have to add more switches – hence more cost. And you lose a dynamic range of operation so you've triggered problems with constraints on your input or output voltage.So the trade-off is whether the constraints of complex silicon outweigh any perceived risks associated with using the new technology. Power Integrations believes that that new technology is proven, reliable and rugged…and also that it delivers the lowest system cost. So we would suggest the GaN solution rather than an LLC, even though we have LLC ICs in our toolbox too. We recommend a simple GaN flyback over a more complex resonant supply simply because of the flexibility that the flyback provides.Q: What are the key packaging considerations wide bandgap semiconductors, and how can they be addressed?Power Integrations is a sub-systems company, not a GaN transistor company: we integrate the switch, GaN, SiC or silicon, into a package along with other functions to deliver an integrated power solution. We're not trying to make the best package to address the needs of a power FET, we're creating the best package for a multi chip sub-system for a small flyback power supply, a PFC device or an LED driver. As such, our packaging challenge is unique. But a founding principle of Power Integrations was to minimize the number of pins and the size of the package, bearing in mind constraints about creepage, so WBG has not changed our approach in this respect.With this in mind, Power Integrations produces custom packages that are most suitable for power at an electrical and thermal and mechanical level. When we design a package, we consider:&nbsp;“Is it going to be isolated?”“Will it conduct the heat away properly?”&nbsp;“Is it strong enough to resist moisture?”&nbsp;“Will it pass the usual basket of JEDEC and automotive tests?”Power Integrations is continually innovating in packaging. As an example, a few years ago, we introduced Fluxlink™, a communication technology that enables feedback to be delivered across an isolation barrier without the use of any magnetic materials or an optocoupler. FluxLink delivers a very high communication bandwidth which enables a much faster load-transient response. But because FluxLink is a leadframe-based approach, we use standard stamping tools and standard transfer-molding technology. Therefore, we don't we don't incur any cost penalty, despite using a multichip module approach.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1708323841620-ezgif-2-7cf67576ee.jpg" style="width: 766px;" class="fr-fic fr-dib">Q: How can thermal management be optimized in a high-power wide bandgap semiconductor device to ensure reliable operation?A general comment concerning thermal management is that Power Integrations has found that more GaN is cheaper than more aluminum. In other words, it's better to increase the size of the GaN transistor and generate less heat in the first place than to attempt a mechanical thermal heatsink-plus-fan solution afterwards. Milligrams of GaN is cheaper than kilograms of aluminum.&nbsp;Specifically, one of the most important design considerations is to ensure that the heat sink is at source - i.e. it's grounded. So Power Integrations makes sure that its devices have a large amount of metal from the lead frame of the package exposed and available to be soldered down. Sometimes we have a pad on the back of the part, sometimes we have a tab on one side. Our devices feature a grounded tab, so there is no hot, high voltage heat sink that is switching up and down at high frequency, radiating on a broad spectrum of frequencies causing EMI problems. &nbsp;Q: How will the use of wide bandgap semiconductor devices develop in the power electronics industry?Because GaN approaches the ideal switch, my view is that when GaN can, GaN should. I see GaN basically taking over at the lower voltages - mains through to 1200 volts; essentially GaN will become ubiquitous up to a certain power level, especially for applications that need to be efficient across the load range. It's dependent on the technical development of GaN: as the voltage of GaN increases it will replace silicon carbide, and as its current carrying capacity increases, GaN will replace IGBTs.

In the in-depth interview, PI Vice President of Marketing Doug Bailey explains GaN technology and the new possibilities it brings to the power conversion industry.

GaN set to become ubiquitous in power electronics

In diamonds (and other semiconducting materials), defects are a quantum sensor’s best friend.That’s because defects, essentially a jostled arrangement of atoms, sometimes contain electrons with an angular momentum, or spin, that can store and process information. This “spin degree of freedom” can be harnessed for a range of purposes, such as sensing magnetic fields or making a quantum network.Researchers led by&nbsp;<a href="http://fuchs.research.engineering.cornell.edu/fuchs" target="_blank">Greg Fuchs</a>, Ph.D. ’07, professor of applied and engineering physics in Cornell Engineering, went searching for such a spin in the popular semiconductor gallium nitride and found it, surprisingly, in two distinct species of defect, one of which can be manipulated for future quantum applications.The group’s paper, “<a href="https://www.nature.com/articles/s41563-024-01803-5" target="_blank">Room Temperature Optically Detected Magnetic Resonance of Single Spins in GaN</a>,” published Feb. 12 in Nature Materials. The lead author is doctoral student Jialun Luo.Defects are what give gems their color, and for this reason they are also known as color centers. Pink diamonds, for example, get their hue from defects called nitrogen vacancy centers. However, there are many color centers that have yet to be identified, even in materials that are commonly used.“Gallium nitride, unlike diamond, is a mature semiconductor. It has been developed for wide bandgap high-frequency electronics, and that’s been a very intense effort over many, many years,” Fuchs said. “You can go and buy a wafer of it, it’s in your computer charger, probably, or electric car. But in terms of a material for quantum defects, it has not been explored very much.”In order to search for the spin degree of freedom in gallium nitride, Fuchs and Luo teamed up with&nbsp;<a href="https://www.ece.cornell.edu/faculty-directory/farhan-rana" target="_blank">Farhan Rana</a>, the Joseph P. Ripley Professor of Engineering, and doctoral student Yifei Geng, with whom they had previously explored the material.The group used confocal microscopy to identify the defects via fluorescent probes and then conducted a host of experiments, such as measuring how a defect’s fluorescence rate changes as a function of magnetic field, and using a small magnetic field to drive the defect’s spin resonant transmissions, all at room temperature.“At the beginning, the preliminary data showed signs of interesting spin structures but we couldn’t drive the spin resonance,” Luo said. “It turns out that we needed to know the defect symmetry axes and apply a magnetic field along the correct direction to probe the resonances; the results brought us more questions, waiting to be worked out.”The experiments showed the material had two types of defects with a distinct spin spectra. In one, the spin was coupled to a metastable excited state; in the other, it was coupled to the ground state.In the latter case, the researchers were able to see fluorescence changes of up to 30% when they drove the spin transition – a large change in contrast, and relatively rare, for a quantum spin at room temperature.“Usually the fluorescence and spin are tied together very weakly, so when you change the spin projection, the fluorescence might change by 0.1%, or something very, very tiny,” Fuchs said. “From a technology standpoint, that isn’t great, because you want a big change, so that you can measure it quickly and efficiently.”The researchers then performed a quantum control experiment. They found they could manipulate the ground-state spin and that it had quantum coherence – a quality that allows quantum bits, or qubits, to retain their information.“That’s something that is pretty exciting about this observation,” Fuchs said. “There’s still a lot of fundamental work to do, and there’s many more questions than there are answers. But the basic discovery of spin in this color center, the fact that it has a strong spin contrast up to 30%, that it exists in a mature semiconductor material – that opens up all kinds of interesting possibilities that we now are excited to explore.”The research was supported by the <a href="http://www.ccmr.cornell.edu/" target="_blank">Cornell Center for Materials Research</a> (CCMR), with funding from the National Science Foundation’s Materials Research Science and Engineering Center program; the Cornell Engineering Sprout program; and the NSF’s Quantum Sensing Challenges for Transformational Advances in Quantum Systems program.The researchers made use of the&nbsp;<a href="https://www.cnf.cornell.edu/" target="_blank">Cornell NanoScale Facility</a>, also supported by the NSF.

Doctoral student Jialun Luo (left) and Greg Fuchs, Ph.D. ’07, professor of applied and engineering physics in Cornell Engineering, searched for a “spin degree of freedom” in the popular semiconductor gallium nitride and found it, surprisingly, in two distinct species of defect. Credits: Charissa King-O’Brien/Cornell Engineering

In diamonds (and other semiconducting materials), defects are a quantum sensor’s best friend.

Semiconductor defects could boost quantum technology

QFN (quad flat no-leads) technology footprint on PCB

The Quad Flat No-leads (QFN) package is a type of surface-mount technology (SMT) in the electronics industry known for its compact size and high performance. This comprehensive guide explores its benefits (high performance), applications (mobile devices), and challenges (assembly, soldering).

QFN Packages: A Guide to High-Performance Electronics Encapsulation

What happens when you expose tellurite glass to femtosecond laser light? That’s the question that Gözden Torun at the Galatea Lab, in a collaboration with Tokyo Tech scientists, aimed to answer in her thesis work when she made the discovery that may one day turn windows into single material light-harvesting and sensing devices. The results are published in&nbsp;PR Applied.Interested in how the atoms in the tellurite glass would reorganize when exposed to fast pulses of high energy femtosecond laser light, the scientists stumbled upon&nbsp;<a href="https://doi.org/10.1002/adma.202210446" target="_blank" rel="noopener">the formation of nanoscale tellurium and tellurium oxide crystals</a>, both semiconducting materials etched into the glass, precisely where the glass had been exposed. That was the eureka moment for the scientists, since a semiconducting material exposed to daylight may lead to the generation of electricity.“Tellurium being semiconducting, based on this finding we wondered if it would be possible to write durable patterns on the tellurite glass surface that could reliably induce electricity when exposed to light, and the answer is yes,” explains Yves Bellouard who runs EPFL’s Galatea Laboratory. “An interesting twist to the technique is that no additional materials are needed in the process. All you need is tellurite glass and a femtosecond laser to make an active photoconductive material.”Using tellurite glass produced by colleagues at Tokyo Tech, the EPFL team brought their expertise in femtosecond laser technology to modify the glass and analyze the effect of the laser. After exposing a simple line pattern on the surface of a tellurite glass 1 cm in diameter, Torun found that it could generate a current when exposing it to UV light and the visible spectrum, and this, reliably for months.“It’s fantastic, we’re locally turning glass into a semiconductor using light,” says Yves Bellouard. “We’re essentially transforming materials into something else, perhaps approaching the dream of the alchemist!”.<hr>References<a href="https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.21.014008" target="_blank" rel="noopener">https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.21.014008</a>

A photoconductive circuit, where the circuit is directly patterned onto a glass surface with femtosecond laser light - 2024 EPFL / Lisa Ackermann - CC-BY-SA 4.0

EPFL physicists propose a novel way to create photoconductive circuits, where the circuit is directly patterned onto a glass surface with femtosecond laser light. The new technology may one day be useful for harvesting energy, while remaining transparent to light and using a single material.

Turning glass into a 'transparent' light-energy harvester

An international team that includes Rutgers University–New Brunswick scientists has developed a new method to make and manipulate a widely studied class of high-temperature superconductors.This technique should pave the way for the creation of unusual forms of superconductivity in previously unattainable materials.When cooled to a critical temperature, superconductors can conduct electricity without resistance or energy loss. These materials have intrigued physicists for decades because they can achieve a state of perfect conductivity allowing an electric current to flow indefinitely. But most superconductors only exhibit this peculiarity at temperatures so low – a few degrees above absolute zero – which renders them impractical.The new work,&nbsp;<a href="https://www.science.org/doi/abs/10.1126/science.abl8371?af=R" target="_blank">published</a>&nbsp;in Science, describes experiments that grew out of theoretical calculations that included those by a Rutgers team led by&nbsp;<a href="https://sites.rutgers.edu/pixley-group/people/jed-pixley/" target="_blank">Jedediah Pixley</a>, an associate professor in the Department of Physics and Astronomy in the Rutgers School of Arts and Sciences.The experiments confirmed predictions by Pixley and Pavel Volkov, who at the time was a postdoctoral fellow at the Rutgers&nbsp;<a href="https://cmt.rutgers.edu/" target="_blank">Center for Materials Theory</a>. These predictions, based on mathematical models Pixley and Volkov (now at the University of Connecticut) devised to represent the underlying quantum physical behavior,&nbsp;projected&nbsp;how cuprate superconductors would behave if they were placed in proximity in specific configurations and at varying angles.Superconductors are already in use today. Since the 1970s, scientists have employed superconducting magnets to generate the powerful magnetic fields needed for the operation of magnetic resonance imaging (MRI) machines. Maglev trains using the technology were introduced in the 1980s. More recently, scientists have harnessed the power of superconducting magnets to guide electron beams in experimental devices such as synchrotrons and accelerators.In the future, scientists envision a world where ultra-efficient electricity grids, ultrafast and energy-efficient computer chips, and even quantum computers are powered by new kinds of superconducting materials.The new experiments that validated Pixley and Volkov’s ideas were conducted by a team at Harvard University led by professor and physicist Philip Kim.“We took two cuprate superconductors – materials that already were interesting – and, in placing them together and twisting them in a precise way, made something else that was very interesting: another superconductor which could have lots of technological applications,” said Pixley, a condensed matter theorist.Because of its unique properties, the new superconductor is a promising candidate for the world’s first high-temperature,&nbsp;superconducting diode, essentially a switch that controls the flow of electrical current, the researchers said.Such a device could potentially fuel fledgling industries such as quantum computing, which rely on fleeting phenomena produced in materials like superconductors, they added.Pixley, who joined the Rutgers faculty in 2017, earned his doctoral degree by studying the conditions involved in producing superconductivity in unconventional materials. The latest research extends the field of “twistronics,” which involves twisting flat layers of two-dimensional materials to produce physical effects at the subatomic level that are observable on the macroscopic scale.To Pixley, the study enlarges the paradigm of what materials can exhibit superconducting properties when twisted. The work yields other insights, as well.“At the same time, we have found that this leads to a novel type of ‘magnetic’ superconducting state that has been long sought after, showing definitively that different superconducting phases can be reached via a twist," he said.The experimentalists first split an extremely thin film of a superconductive cuprate – nicknamed “BSCCO” and made of bismuth strontium calcium copper oxide – into two layers. Then, maintaining frigid conditions, they stacked the layers at a 45-degree twist, like an ice cream sandwich with askew wafers, retaining superconductivity at the fragile interface.Cuprates are copper oxides that, decades ago, upended the physics world by showing they become superconducting at much higher temperatures than theorists had thought possible. BSCCO is considered a high-temperature superconductor because it starts superconducting at about -288 Fahrenheit. That is very cold by practical standards, but astonishingly high among classical superconductors, which typically must be cooled to about -400 Fahrenheit.The work opens the door to more experiments, Pixley said.“It will be very exciting to extend these experiments to other configurations of superconductors – twisted monolayers and a few twisted multilayers of superconductors at small twist angles,” Pixley said.Other researchers on the study included scientists from the University of British Columbia, Brookhaven National Laboratory, the Leibniz Institute for Solid State and Materials Research in Germany, Seoul National University in South Korea and the National Institute for Materials Science in Japan.

Rutgers theorists have helped pave the way for the creation of superconductivity in previously unattainable materials.

Theory becomes reality when Rutgers–New Brunswick scientists help develop process for twisting materials in ways never thought possible

Researchers Craft New Way to Make High-Temperature Superconductors - With a Twist

Princeton researchers have created an artificial intelligence (AI) tool to predict the behavior of crystalline materials, a key step in advancing technologies like batteries and semiconductors. Although computer simulations are commonly used in crystal design, the new method relies on a large language model, similar to those that power text generators like ChatGPT.By synthesizing information from text descriptions that include details such as the length and angles of bonds between atoms and measurements of electronic and optical properties, the new method can predict properties of new materials more accurately and thoroughly than existing simulations — and potentially speed up the process of designing and testing new technologies.The researchers developed a text benchmark consisting of the descriptions of more than 140,000 crystals from the&nbsp;<a href="https://next-gen.materialsproject.org/" target="_blank">Materials Project</a>, and then used it to train an adapted version of a large language model called T5, originally created by Google Research. They tested the tool’s ability to predict the properties of previously studied crystal structures, from ordinary table salt to silicon semiconductors. Now that they’ve demonstrated its predictive power, they are working to apply the tool to the design of new crystal materials.The&nbsp;<a href="https://arxiv.org/abs/2310.14029" target="_blank">method</a>, presented Nov. 29 at the Materials Research Society’s Fall Meeting in Boston, represents a new benchmark that could help accelerate materials discovery for a wide range of applications, according to senior study author&nbsp;<a href="https://engineering.princeton.edu/faculty/adji-bousso-dieng" target="_blank">Adji Bousso Dieng</a>, an assistant professor of&nbsp;<a href="https://www.cs.princeton.edu/" target="_blank">computer science</a> at Princeton.Existing AI-based tools for crystal property prediction rely on methods called graph neural networks, but these have limited computational power and can’t adequately capture the nuances of the geometry and lengths of bonds between atoms in a crystal, and the electronic and optical properties that result from these structures. Dieng’s team is the first to tackle the problem using large language models, she said.“We have made tremendous advances in computer vision and natural language,” said Dieng, “but we are not very advanced yet when it comes to dealing with graphs [in AI]. So, I wanted to move from the graph to actually translating it to a domain where we have great tools already. If we have text, then we can leverage all these powerful [large language models] on that text.”The language model-based approach “gives us a whole new way to look at the problem” of designing materials, said study coauthor&nbsp;<a href="https://engineering.princeton.edu/faculty/craig-arnold" target="_blank">Craig Arnold</a>, Princeton’s Susan Dod Brown Professor of&nbsp;<a href="https://mae.princeton.edu/" target="_blank">Mechanical and Aerospace Engineering</a> and vice dean for innovation. “It’s really about, how do I access all of this knowledge that humanity has developed, and how do I process that knowledge to move forward? It’s characteristically different than our current approaches, and I think that’s what gives it a lot of power.”For insights into the challenges of crystal design, Dieng and Ph.D. student&nbsp;<a href="https://scholar.google.com/citations?user=5qnTWQEAAAAJ&hl=en" target="_blank">Andre Niyongabo Rubungo</a> teamed up with Arnold and with&nbsp;<a href="https://engineering.princeton.edu/faculty/barry-rand" target="_blank">Barry Rand</a>, a professor of&nbsp;<a href="https://ece.princeton.edu/people/barry-p-rand" target="_blank">electrical and computer engineering</a> and the&nbsp;<a href="https://acee.princeton.edu/" target="_blank">Andlinger Center for Energy and the Environment</a> who focuses on materials for semiconductors and solar energy. Arnold is interested in laser-material interactions, with applications for energy storage.“The materials in our world are all ones that were developed through scientific hypothesis testing and sometimes luck,” said Rand. This process “leads to good outcomes, but it takes time. Through artificial intelligence methods, we could really accelerate that.” Furthermore, he said, “it allows us to identify things that probably we as humans wouldn’t intuit.”Given a crystal with a particular composition of chemical elements, the team’s method can predict properties including the band gap, which relates to the crystal’s electronic states and conductivity.“If you can predict that with high accuracy, when you then go to do the painstaking work of experimentation, you can have more confidence that it’s going to yield success,” said Rand.Ph.D. student Rubungo received a&nbsp;<a href="https://www.mrs.org/meetings-events/fall-meetings-exhibits/2023-mrs-fall-meeting/meeting-events/other/poster-sessions" target="_blank">best poster award</a> for presenting the work to materials researchers at the fall meeting. Many were surprised by the power of large language models in this context. The field is more accustomed to structured data used as inputs for graph neural networks, but “texts are easier to deal with,” said Rubungo. “It’s easier to include the information you want in your description, and to modify the tool and remove what you don’t want. People were very excited to see that.”As a new tool, he noted, the prediction method has limitations. It uses more computing power and is slower than graph neural networks typically used for this purpose. It could also benefit from expanded training data to boost its ability to predict properties of novel materials.Dieng is pursuing collaborations with other materials researchers, and aims to move the work beyond crystals to a broader variety of materials. “This is a nascent area of research, and what advances research is to have a well-established benchmark that’s well curated,” she said. “We are gathering more data sets into one benchmark that will be hosted at Princeton for researchers to use.”<hr>The paper, “<a href="https://arxiv.org/abs/2310.14029" target="_blank">LLM-Prop: Predicting Physical And Electronic Properties Of Crystalline Solids From Their Text Descriptions</a>,” was presented Nov. 29 at the Materials Research Society’s Fall Meeting. Support for the research was provided by the Schmidt DataX Fund at Princeton University, the Schmidt Futures AI2050 Early Career Fellowship, and the U.S. National Science Foundation.

A scanning electron microscope image of tin crystals, stimulated by electricity and growing on a copper surface. A new method developed by Princeton researchers could speed up the process of designing and testing new crystalline materials. Image by Lynn Trahey, Argonne National Laboratory

Princeton researchers have created an artificial intelligence (AI) tool to predict the behavior of crystalline materials, a key step in advancing technologies like batteries and semiconductors. 

Researchers harness large language models to accelerate materials discovery

The world of PCB connectors is diverse and expansive, catering to various applications in the field of electronics. In this article, we’ll dive and explore from the basics of board-to-board and wire-to-board connector types, to specialty connectors designed for specific use cases.

Types of PCB Connectors: An In-Depth Guide

An insight into preventing perovskite semiconductors from degrading quickly, discovered at the University of Michigan, could help enable solar cells estimated to be <a href="https://solarmagazine.com/solar-panels/perovskite-solar-cells/" target="_blank" rel="noreferrer noopener">two to four times cheaper</a> than today’s thin-film solar panels.&nbsp;Perovskites may also be combined with the silicon-based semiconductors that are prevalent in today’s solar panels to create <a href="https://www.nature.com/articles/d41586-023-03714-y" target="_blank" rel="noreferrer noopener">“tandem” solar cells</a> that could surpass the maximum theoretical efficiency of silicon solar cells.“Silicon solar cells are great because they are very efficient and can last for a very long time, but the high efficiency comes with a high cost,” said <a href="https://che.engin.umich.edu/people/gong-xiwen/" target="_blank" rel="noreferrer noopener">Xiwen Gong</a>, U-M assistant professor of chemical engineering. “To make high-purity silicon, temperatures over 1,000 degrees Celsius are needed. Otherwise, the efficiency won’t be as good.”The high temperature comes with higher economic and environmental costs. But while perovskites can be produced at lower temperatures, they degrade when exposed to heat, moisture and air. As a result, the lifespan of perovskite today is too short to be commercially competitive in solar panels.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1705965138185-solar-cell-1.jpg" style="width: 300px;" class="fr-fic fr-dib">Perovskite solar cells like this one, made by Xiwen Gong’s group, could make solar energy cheaper and more environmentally friendly—but they degrade faster than silicon. In a study published in the journal Matter, the team discovered how to make the black perovskite film last longer. Photo credit: Zhengtao Hu, Gong Lab, University of Michigan.Gong’s research aims to make hardier perovskite solar cells, and her latest study published in the journal Matter&nbsp;suggests that bulky “defect pacifying” molecules are best at increasing the perovskites’ stability and overall lifespan.Perovskite crystals contain lead atoms that aren’t fully bound to the other components within the perovskite. Such “undercoordinated sites” are defects often found on the crystal surfaces and at grain boundaries where there’s a break in the crystal lattice. These defects hinder the movement of electrons and speed up the decay of the perovskite material.&nbsp;Engineers already know that mixing defect pacifying molecules into the perovskites can help lock up the undercoordinated lead, in turn preventing other imperfections from forming at high temperatures. But until now, engineers didn’t know exactly how a given molecule affected the hardiness of perovskite cells.“We wanted to figure out what features on the molecules specifically improve the perovskite’s stability,” said Hongki Kim, a former postdoctoral researcher in chemical engineering and one of the study’s first authors.To investigate the problem, Gong’s team created three additives with a range of shapes and sizes and added them into thin films of perovskite crystals, which can absorb light and convert it to electricity. Each additive contained the same or similar chemical building blocks, which made size, weight and arrangement the main properties differentiating them.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1705965160076-Perovskite-Additive-Diagram-.jpg" style="width: 300px;" class="fr-fic fr-dib">Xiwen Gong’s team designed three molecular additives to study the impact of size and configuration on the stability of perovskite films—a material class crucial for creating efficient and cost-effective solar cells. These additives hinder the growth of defects at perovskite crystal lattice breaks, known as grain boundaries, ultimately enhancing solar cell efficiency. The bulkiest molecule effectively covers surface defects on perovskite grains, simultaneously increasing grain size during manufacturing. Larger grains lead to fewer grain boundaries, reducing potential defect sites. Image credit: Carlos A. Figueroa Morales, Gong Lab, University of Michigan.Then, the team measured how strongly the different additives interacted with perovskites and consequently influenced the formation of defects in the films. Larger molecules by mass were better at sticking to the perovskite because they had more binding sites that interact with perovskite crystals. As a result, they tended to be better at preventing defects from forming.But the best additives also needed to take up a lot of space. Large but skinny molecules resulted in smaller perovskite grains during the manufacturing process. Smaller grains aren’t ideal because they also create perovskite cells with more grain boundaries, or more areas for defects to form. In contrast, bulky molecules forced larger perovskite grains to form, which in turn reduced the density of grain boundaries in the film.Heating the perovskite films to over 200 degrees Celsius confirmed that bulky additives helped the films retain more of their characteristic slate black color and develop fewer structural defects.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1705965183557-Carlos-in-lab.jpg" style="width: 766px;" class="fr-fic fr-dib">Doctoral student Carlos Alejandro Figueroa Morales places a perovskite thin film sample into a spectrometer that measures the light-emitting properties of the perovskites. Changes in how the perovskite films emit light when made with the different additive molecules can reveal how many defects are inside the perovskite. Photo credit: Zhengtao Hu, Gong Lab, University of Michigan.“Both the size and configuration are important when designing additives, and we believe this design philosophy could be implemented across various perovskite formulations to further improve the lifetime of perovskite solar cells, light emitting devices and photodetectors,” said Carlos Alejandro Figueroa Morales, a doctoral student in macromolecular science and engineering and one of the study’s first authors.<hr>Xiwen Gong is also an assistant professor of electrical and computer engineering, materials science and engineering, macromolecular science and engineering, and applied physics. The research was funded by the University of Michigan and relied on a <a href="https://www.nsf.gov/awardsearch/showAward?AWD_ID=1625671&HistoricalAwards=false" target="_blank" rel="noreferrer noopener">scanning electron microscope</a> funded by the National Science Foundation. Co-author Nancy Muyanja led the microscopy measurements at the <a href="https://mc2.engin.umich.edu/" target="_blank" rel="noreferrer noopener">Michigan Center for Materials Characterization</a>.

The findings could help engineers methodically find the best molecules to increase the lifespan of perovskite solar cells, rather than relying on time-consuming trial and error.

Bulky additives could make cheaper solar cells last longer

 A semiconductor chip designed via tapeout

Unveiling the Evolution, History, and Significance of the Tapeout Process in Semiconductor Manufacturing.

Tapeout in Semiconductor Manufacturing: An In-depth Exploration

Circuit board components or SMDs etched on an electronic board

This guide provides an in-depth understanding of circuit board components, highlighting their basics, types, design process, and troubleshooting for various applications.

Understanding Circuit Board Components: A Comprehensive Guide

Electronic circuit chip (fabricated through chemical etching)

Chemical etching uses acidic chemicals to remove material and create an etched pattern on a metal surface. This article delves into the fundamental processes of chemical etching,  its myriad applications, and nuanced techniques employed to achieve precision and perfection in the final product.


Chemical Etching: A Comprehensive Guide to Processes, Applications, and Techniques

Researchers at the Georgia Institute of Technology have created the world’s first functional semiconductor made from graphene, a single sheet of carbon atoms held together by the strongest bonds known. Semiconductors, which are materials that conduct electricity under specific conditions, are foundational components of electronic devices. The team’s breakthrough throws open the door to a new way of doing electronics.Their <a href="https://www.youtube.com/watch?v=gWUX2OTqkEo" target="_blank">discovery</a> comes at a time when silicon, the material from which nearly all modern electronics are made, is reaching its limit in the face of increasingly faster computing and smaller electronic devices. <a href="https://physics.gatech.edu/user/walter-de-heer" target="_blank">Walter de Heer</a>, Regents’ Professor of <a href="https://physics.gatech.edu/" target="_blank">physics</a> at Georgia Tech, led a team of researchers based in Atlanta, Georgia, and Tianjin, China, to produce a graphene semiconductor that is compatible with conventional microelectronics processing methods — a necessity for any viable alternative to silicon.<iframe width="640" height="360" src="https://www.youtube.com/embed/gWUX2OTqkEo?&amp;wmode=opaque&amp;rel=0&amp;enablejsapi=1&amp;origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe>In this latest research, <a href="https://www.nature.com/articles/s41586-023-06811-0" target="_blank" id="isPasted">published in Nature</a>, de Heer and his team overcame the paramount hurdle that has been plaguing graphene research for decades, and the reason why many thought graphene electronics would never work. Known as the "band gap", it is a crucial electronic property that allows semiconductors to switch on and off. Graphene didn't have a band gap – until now.&nbsp;"We now have an extremely robust graphene semiconductor with 10 times the mobility of silicon, and which also has unique properties not available in silicon," de Heer said. "But the story of our work for the past 10 years has been, 'Can we get this material to be good enough to work?'"&nbsp;<h2 id="isPasted">A New Type of Semiconductor</h2><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1704463112860-furnace.jpg" style="width: 300px;" class="fr-fic fr-dib">De Heer started to explore carbon-based materials as potential semiconductors early in his career, and then made the switch to 2D graphene in 2001. He knew at that time that graphene had potential for electronics."We were motivated by the hope of introducing three special properties of graphene into electronics," he said. "It's an extremely robust material, one that can handle very large currents, and can do so without heating up and falling apart."<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1704463145678-disco-ball-2a.png" style="width: 300px;" class="fr-fic fr-dib">De Heer achieved a breakthrough when he and his team figured out how to grow graphene on silicon carbide wafers using special furnaces. They produced epitaxial graphene, which is a single layer that grows on a crystal face of the silicon carbide. The team found that when it was made properly, the epitaxial graphene chemically bonded to the silicon carbide and started to show semiconducting properties.Over the next decade, they persisted in perfecting the material at Georgia Tech and later in collaboration with colleagues at the Tianjin International Center for Nanoparticles and Nanosystems at Tianjin University in China. De Heer founded the center in 2014 with Lei Ma, the center’s director and a co-author of the paper.<h3>How They Did It</h3>In its natural form, graphene is neither a semiconductor nor a metal, but a semimetal. A band gap is a material that can be turned on and off when an electric field is applied to it, which is how all transistors and silicon electronics work. The major question in graphene electronics research was how to switch it on and off so it can work like silicon.But to make a functional transistor, a semiconducting material must be greatly manipulated, which can damage its properties. To prove that their platform could function as a viable semiconductor, the team needed to measure its electronic properties without damaging it.They put atoms on the graphene that "donate" electrons to the system — a technique called doping, used to see whether the material was a good conductor. It worked without damaging the material or its properties.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1704463161937-notebook-working.jpg" style="width: 300px;" class="fr-fic fr-dib">The team's measurements showed that their graphene semiconductor has 10 times greater mobility than silicon. In other words, the electrons move with very low resistance, which, in electronics, translates to faster computing. "It's like driving on a gravel road versus driving on a freeway," de Heer said. "It's more efficient, it doesn't heat up as much, and it allows for higher speeds so that the electrons can move faster."The team’s product is currently the only two-dimensional semiconductor that has all the necessary properties to be used in nanoelectronics, and its electrical properties are far superior to any other 2D semiconductors currently in development.&nbsp;"A long-standing problem in graphene electronics is that graphene didn’t have the right band gap and couldn’t switch on and off at the correct ratio,” said Ma. “Over the years, many have tried to address this with a variety of methods. Our technology achieves the band gap, and is a crucial step in realizing graphene-based electronics."<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1704463180843-silicon.jpg" style="width: 300px;" class="fr-fic fr-dib"><h3 id="isPasted">Moving Forward<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1704463198199-graphene-bottle.jpg" style="width: 300px;" class="fr-fic fr-dib"> </h3>Epitaxial graphene could cause a paradigm shift in the field of electronics and allow for completely new technologies that take advantage of its unique properties. The material allows the quantum mechanical wave properties of electrons to be utilized, which is a requirement for quantum computing."Our motivation for doing graphene electronics has been there for a long time, and the rest was just making it happen," de Heer said. "We had to learn how to treat the material, how to make it better and better, and finally how to measure the properties. That took a very, very long time."<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1704463217513-chip-in-box_0.jpg" style="width: 300px;" class="fr-fic fr-dib">According to de Heer, it is not unusual to see yet another generation of electronics on its way. Before silicon, there were vacuum tubes, and before that, there were wires and telegraphs. Silicon is one of many steps in the history of electronics, and the next step could be graphene."To me, this is like a Wright brothers moment," de Heer said. "They built a plane that could fly 300 feet through the air. But the skeptics asked why the world would need flight when it already had fast trains and boats. But they persisted, and it was the beginning of a technology that can take people across oceans."<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1704463293235-ezgif-4-c7538c2cac.jpg" style="width: 300px;" class="fr-fic fr-dib"><hr>Citation: Zhao, J.&nbsp;et al. Ultrahigh-mobility semiconducting epitaxial graphene on silicon carbide.&nbsp;Nature (2024).DOI: <a href="https://doi.org/10.1038/s41586-023-06811-0" target="_blank">https://doi.org/10.1038/s41586-023-06811-0</a>Video and Photos: Chris McKenney

The technology could allow for smaller and faster electronic devices and may have applications for quantum computing.

Researchers Create First Functional Semiconductor Made From Graphene

Nordic Semiconductor-Fri Jun 30 2023 23:59:59 GMT+0200 (Central European Summer Time)

Nordic Semiconductor-Mon Jul 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Nordic Semiconductor-Thu Aug 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Nordic Semiconductor-Thu Aug 31 2023 23:59:59 GMT+0200 (Central European Summer Time)

Nordic Semiconductor-Sat Sep 30 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Nordic Semiconductor-Tue Oct 31 2023 23:59:59 GMT+0200 (Eastern European Standard Time)

Renesas Electronics-Fri Jun 30 2023 23:59:59 GMT+0200 (Central European Summer Time)

Renesas Electronics-Mon Jul 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Renesas Electronics-Thu Aug 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Renesas Electronics-Thu Aug 31 2023 23:59:59 GMT+0200 (Central European Summer Time)

Renesas Electronics-Sat Sep 30 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Mouser Electronics-Fri Jun 30 2023 23:59:59 GMT+0200 (Central European Summer Time)

Mouser Electronics-Mon Jul 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Mouser Electronics-Thu Aug 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Mouser Electronics-Thu Aug 31 2023 23:59:59 GMT+0200 (Central European Summer Time)

Mouser Electronics-Sat Sep 30 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Mouser Electronics-Mon Oct 30 2023 14:34:39 GMT+0200 (Eastern European Standard Time)

Mouser Electronics-Tue Oct 31 2023 23:59:59 GMT+0200 (Eastern European Standard Time)

Ansys-Fri Jun 30 2023 23:59:59 GMT+0200 (Central European Summer Time)

Ansys-Mon Jul 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Ansys-Thu Aug 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Ansys-Thu Aug 31 2023 23:59:59 GMT+0200 (Central European Summer Time)

Ansys-Sat Sep 30 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Ansys-Fri Oct 06 2023 08:49:31 GMT-0500 (Eastern Standard Time)

Ansys-Tue Oct 31 2023 23:59:59 GMT+0200 (Eastern European Standard Time)

Ansys-Mon Oct 30 2023 08:45:26 GMT-0400 (Eastern Daylight Time)

Alif Semiconductor-Fri Jun 30 2023 23:59:59 GMT+0200 (Central European Summer Time)

Alif Semiconductor-Mon Jul 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Alif Semiconductor-Thu Aug 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Alif Semiconductor-Thu Aug 31 2023 23:59:59 GMT+0200 (Central European Summer Time)

Alif Semiconductor-Sat Sep 30 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

USound GmbH-Fri Jun 30 2023 23:59:59 GMT+0200 (Central European Summer Time)

USound GmbH-Mon Jul 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

USound GmbH-Thu Aug 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

USound GmbH-Thu Aug 31 2023 23:59:59 GMT+0200 (Central European Summer Time)

USound GmbH-Sat Sep 30 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Intrinsic ID-Fri Jun 30 2023 23:59:59 GMT+0200 (Central European Summer Time)

Intrinsic ID-Mon Jul 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Intrinsic ID-Thu Aug 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Intrinsic ID-Thu Aug 31 2023 23:59:59 GMT+0200 (Central European Summer Time)

Intrinsic ID-Sat Sep 30 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Infineon-Fri Jun 30 2023 23:59:59 GMT+0200 (Central European Summer Time)

Infineon-Mon Jul 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Infineon-Thu Aug 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Infineon-Thu Aug 31 2023 23:59:59 GMT+0200 (Central European Summer Time)

Infineon-Sat Sep 30 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Infineon-Tue Oct 31 2023 23:59:59 GMT+0200 (Eastern European Standard Time)

Nexperia-Fri Jun 30 2023 23:59:59 GMT+0200 (Central European Summer Time)

Nexperia-Mon Jul 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Nexperia-Thu Aug 31 2023 23:59:59 GMT+0200 (Central European Summer Time)

Nexperia-Thu Aug 31 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Nexperia-Sat Sep 30 2023 23:59:59 GMT+0300 (Eastern European Summer Time)

Nexperia-Fri Oct 06 2023 08:49:31 GMT-0500 (Eastern Standard Time)

Nexperia-Tue Oct 31 2023 23:59:59 GMT+0200 (Eastern European Standard Time)

Nexperia-Mon Oct 30 2023 08:42:36 GMT-0400 (Eastern Daylight Time)

Nexperia-Mon Oct 30 2023 08:43:01 GMT-0400 (Eastern Daylight Time)

Nexperia-Mon Oct 30 2023 08:43:41 GMT-0400 (Eastern Daylight Time)

semiconductors

semiconductors

Profiles