Computational Screening Identifies Novel Ultra-Wide Bandgap Semiconductors For RF Electronics

The relentless pursuit of faster, more efficient electronics demands materials that can operate at increasingly high frequencies and power levels, a challenge current gallium nitride technology is beginning to meet its match with. Emily Garrity, Theodora Ciobanu, and colleagues at Colorado School of Mines and the National Renewable Energy Laboratory address this need by computationally screening a vast landscape of potential semiconductor materials. Their research reveals a wealth of promising alternatives to existing technologies, focusing on materials with ultra-wide band gaps that could significantly improve performance in applications ranging from electric vehicle chargers to next-generation communication systems and radar. By combining calculations of key performance metrics with assessments of material feasibility, this work establishes a crucial foundation for discovering and developing semiconductors capable of pushing the boundaries of high-frequency electronics.

Power devices require efficient operation at higher power levels and switching frequencies while remaining compact. Current gallium nitride (GaN) semiconductor devices alone cannot meet all these demands. Emerging ultra-wide band gap (UWBG) alternatives, such as diamond, boron nitride, aluminum nitride, and gallium oxide, face significant challenges including limited availability, doping difficulties, and thermal management constraints. This work conducts a high-throughput computational screening for new semiconductors suitable for high-frequency electronics. The analysis computes modeled Johnson and Baliga high-frequency figures of merit in combination with thermal conductivity to assess their potential.

Ternary Oxide Screening for Power Electronics

This research summarizes a series of studies focused on identifying and evaluating materials for high-power electronics, particularly wide and ultra-wide bandgap semiconductors. The core goal is to find alternatives to silicon, silicon carbide, and GaN, addressing limitations in power handling, frequency, and material availability. Materials with larger bandgaps offer higher breakdown voltages, enabling higher power handling and operation at higher temperatures. Concerns about material supply and reliance on critical elements drive the search for more abundant and sustainable alternatives. The researchers employ computational methods, including Density Functional Theory and Monte Carlo simulations, to screen a vast number of materials, predicting their properties before experimental synthesis.

This significantly accelerates the materials discovery process. The initial focus is on ternary oxides, compounds containing three elements with oxygen as one, due to their potential for stability, tunable properties, and relative abundance. The computational screening assesses properties like bandgap, electron/hole mobility, effective mass, stability, and defect chemistry. Several ternary oxides, including AlGaN, Ga2O3, and In2O3, are identified as promising candidates. Ga2O3, in particular, stands out due to its large bandgap, relative abundance, and potential for high breakdown voltage.

Research continues to optimize AlGaN properties and address challenges in growth and doping. The study also investigates In2(Si,Ge)2O7, ZnGeN2, and ZnSiN2 for their potential in device applications. Key research directions include achieving effective p-type doping in WBG materials, controlling defects for optimized performance, developing reliable growth and fabrication methods, and efficiently dissipating heat from WBG devices. Ensuring long-term stability and refining computational models to accurately predict material properties are also crucial. In essence, this research represents a systematic effort to identify and evaluate next-generation materials for high-power electronics, leveraging computational methods to accelerate discovery and address the limitations of existing technologies. The focus on ternary oxides and other promising compounds offers a pathway towards more efficient, reliable, and sustainable power devices.

Computational Screening Identifies Promising Semiconductor Materials

Researchers are actively seeking materials to surpass the limitations of current semiconductors like gallium nitride (GaN), which is approaching its performance limits in high-frequency and high-power applications. While GaN excels in many areas, it struggles to maintain efficiency at very high switching speeds and power levels needed for emerging technologies such as electric vehicle chargers, wireless power transfer, and advanced communication systems. Existing alternatives, including diamond, boron nitride, and aluminum nitride, present challenges related to manufacturing, cost, and achieving the necessary material quality for practical devices. To address these limitations, scientists have undertaken a large-scale computational screening of over 1300 potential semiconductor materials.

This research focuses on identifying compounds with superior figures of merit for both power and radio frequency (RF) applications, considering factors like electrical conductivity, breakdown strength, and thermal management. The results demonstrate a wealth of promising candidates beyond the commonly explored materials, offering significant improvements in performance compared to silicon, silicon carbide, and even GaN. Specifically, the study highlights materials with predicted performance exceeding that of current technologies by orders of magnitude. For example, indium borate (InBO3) exhibits a predicted performance over 6000 times greater than silicon in key metrics for power electronics.

Researchers are now investigating the feasibility of growing these materials as high-quality thin films and controlling their electrical properties through doping, a crucial step towards realizing practical devices. This work lays the foundation for a new generation of semiconductors capable of pushing the boundaries of efficiency and performance in a wide range of applications. The research extends beyond simply identifying promising materials; it also considers the practical challenges of manufacturing and integration. The team is evaluating dopability and growth feasibility, recognizing that a material’s theoretical potential is only valuable if it can be reliably produced and incorporated into devices. This holistic approach, combining computational screening with experimental validation, is essential for accelerating the development of next-generation semiconductor technologies.

New Semiconductors for High-Frequency Electronics

This research presents a high-throughput computational screening that identifies numerous alternative semiconductor materials to gallium nitride (GaN) for use in high-frequency power and radio frequency (RF) electronics. The study demonstrates that a wide range of materials exhibit promising characteristics for these applications, potentially overcoming limitations currently faced with existing technologies. By assessing modeled Johnson and Baliga figures of merit in combination with thermal conductivity, the team identified candidates suitable for both high power and high switching frequency devices. Notably, the researchers found several materials, including InBO3, In2Si2O7, In2Ge2O7, and ZnGeN2, for which dopability has already been predicted, suggesting they are particularly promising for further investigation.

Realizing devices based on these new semiconductors could lead to advancements in areas such as faster electric vehicle chargers, improved wireless power transfer, and enhanced RF systems for next-generation communications and radar technologies. The authors recognize that further work is needed to fully realize the potential of these materials, and they highlight the importance of assessing dopability and achieving successful thin film growth. They also note that identifying suitable contacts and complementary materials for heterostructures will be crucial for device fabrication. This study provides a valuable foundation for materials discovery and opens up new avenues for innovation in high-frequency electronics.