#nitrides

One tiny diode could shrink image sensors by adding memory and processing

P-n diodes are two-terminal devices that consist of two types of semiconductor materials (i.e., a p-type and an n-type material) joined together. These components allow electric current to only move in one direction, which is central to the functioning of many electronic circuits. Conventional p-n diodes only perform a single function, namely that of enabling the flow of current in one direction. This means that other components are required to also perform computations, store data or detect specific signals. Researchers at University of Science and Technology of China and McGill University in Canada recently designed a new p-n diode that can perform three different functions without the need to be integrated with additional components. Their device, presented in a paper published in Nature Electronics, is based on one-dimensional (1D), gallium nitride (GaN) and aluminum gallium nitride (AlGAN)-based structures known as nanowires.

Focused helium ions create ferroelectric regions in aluminum nitride for lower-power chips

Scientists at the Department of Energy's Oak Ridge National Laboratory have shown for the first time that ferroelectricity can be directly written into aluminum nitride using a tightly focused helium ion beam at the Center for Nanophase Materials Sciences (CNMS), a DOE Office of Science user facility at ORNL. Ferroelectric devices don't need constant power to store data, which allows for devices that are more reliable and less power consuming than what's currently available. The study, published in Advanced Materials, represents a new processing approach for wurtzite III-V nitrides, a class of semiconductors already widely used in microelectronics but whose ferroelectric potential has only been recognized since 2019.

A mechanical blue LED: Stretching GaN shifts light from UV to blue without changing chemistry

A research team from the Faculty of Engineering at the University of Hong Kong (HKU) has successfully used mechanical stretching technology to dynamically control the emission color of gallium nitride (GaN) material from ultraviolet (UV) to blue light. This technological breakthrough provides a new semiconductor material control solution for future advanced power transistors, optoelectronic components, radio frequency components, and micro-LED displays. The findings have been published in Physical Review X in a paper titled "Deep Elastic Strain Engineering of Free-Standing GaN Microbridge." Led by Professor Yang Lu from the Department of Mechanical Engineering, the team utilized micro-nano processing technology to fabricate single-crystalline GaN material into tiny bridge-like structures.

Establishing design principles for achieving ultralow thermal conductivity via controlled chemical disorder

A major challenge in thermal-management and thermal-insulation technologies, across multiple industries, is the lack of materials that simultaneously offer low thermal conductivity, mechanical robustness, and scalable fabrication routes. Discovering materials that exhibit completely insulating thermal behavior—or, conversely, extraordinarily high thermal conductivity—has long been a dream for researchers in materials physics. Traditionally, amorphous materials are known to possess very low thermal conductivity. This naturally leads to an important question: Can a crystalline material be engineered to achieve thermal conductivity close to that of an amorphous solid? Such a material would preserve the structural stability of a crystal while achieving exceptionally low thermal conductivity.

Newly discovered metallic material with record thermal conductivity upends assumptions about heat transport limits

A UCLA-led, multi-institution research team has discovered a metallic material with the highest thermal conductivity measured among metals, challenging long-standing assumptions about the limits of heat transport in metallic materials. Published in Science, the study was led by Yongjie Hu, a professor of mechanical and aerospace engineering at the UCLA Samueli School of Engineering. The team reported that metallic theta-phase tantalum nitride conducts heat nearly three times more efficiently than copper or silver, the best conventional heat-conducting metals. Why thermal conductivity matters in electronics Thermal conductivity describes how efficiently a material can carry heat. Materials with high thermal conductivity are essential for removing localized hotspots in electronic devices, where overheating limits performance, reliability and energy efficiency. Copper currently dominates the global heat-sink market, accounting for roughly 30% of commercial thermal-management materials, with a thermal conductivity of about 400 watts per meter-kelvin.

Aluminum nitride transistor advances next-gen RF electronics

Cornell researchers have developed a new transistor architecture that could reshape how high-power wireless electronics are engineered, while also addressing supply chain vulnerabilities for a critical semiconductor material. The device, called an XHEMT, includes an ultra-thin layer of gallium nitride built on bulk single-crystal aluminum nitride, a semiconductor material with low defect densities and an ultrawide bandgap—properties that allow it to withstand higher temperatures and voltages while reducing electrical losses. The device was detailed in the journal Advanced Electronic Materials and the research was co-led by Huili Grace Xing, the William L. Quackenbush Professor, Debdeep Jena, the David E. Burr Professor—both in the School of Electrical and Computer Engineering, the Department of Materials Science and Engineering, and the Kavli Institute at Cornell for Nanoscale Science—and doctoral student Eungkyun Kim.

Do-it-yourself ammonia production: Renewable-powered system uses calcium to reduce emissions and scale for farmers

The last time you scrubbed a streaky window or polished a porcelain appliance, you probably used a chemical called ammonia. Also known as ammonium hydroxide when mixed with water, ammonia is more than a common household cleaner. More than 170 million metric tons of it are produced globally every year, with most of it ending up as fertilizer for corn, cotton and soybeans. UIC researchers are scaling up a system for farmers to produce ammonia in their own backyards. The method, which uses renewable electricity and Earth's natural resources, appears in the journal Proceedings of the National Academy of Sciences.

First wurtzite-structured MgSiN₂ thin film unlocks promising electronic properties

Wurtzite-structured crystals, characterized by their hexagonal symmetry, are widely valued for their unique electronic and piezoelectric properties—their ability to generate an electric charge when subjected to mechanical stress. Among these, gallium nitride (GaN), a key material in blue light-emitting diodes, and aluminum nitride (AlN), used in high-frequency radio frequency (RF) filters in smartphones, are prominent examples. These materials play a crucial role in advanced semiconductors, sensors, and actuators. Scientists at the Institute of Science Tokyo (Science Tokyo), Japan, have made a significant breakthrough in expanding the wurtzite structure to include heterovalent ternary nitrides, specifically for potential piezoelectric and ferroelectric applications. Their paper, which was made available on February 6, 2025, in Advanced Electronic Materials, describes the fabrication of the first-ever magnesium silicon nitride (MgSiN2) heterovalent nitride in a wurtzite structure with piezoelectric properties.