Wide bandgap (WBG) semiconductors offer the potential to deliver electronic devices and systems with advanced power handling performance beyond that achievable in silicon. This stems from their intrinsic ability to operate at higher voltages as directly attributed to their larger semiconductor bandgap. Although excellent progress has been made in the development of WBG technologies GaN and SiC, new and emerging materials with even larger bandgap (so called ultra-wide bandgap semiconductors) offer even greater potential performance gains. Maximising such high-power handling capability in electronic components is essential to address many of the energy and environmental-related challenges that we currently face. For instance, advanced high-power solid-state systems will be required to enable smart power grids for future distribution of electricity and for efficient voltage conversion in electric vehicles. High power systems operating at high frequencies will also be required to meet the performance demands of future communication (e.g. 5G and 6G mobile comms) and radar systems.

Beta-Ga2O3 is an ultra-wide bandgap (UWBG) material with a bandgap even larger than existing WBG technologies, GaN and SiC and hence offers the potential to deliver superior high power performance. Large area beta-Ga2O3 wafers may also be produced using similar processes to silicon, thus offering greater potential for large scale, cost effective manufacture compared to other WBG and UWBG materials. Beta-Ga2O3 is therefore currently in a unique position to meet many of the ever-increasing demands and performance requirements imposed by the continued development of high-power electronic systems. The intrinsic material properties of beta-Ga2O3 also suggest it may be able to operate at high switching speeds, thus allowing for simultaneous high power and high frequency (GHz) operation. Little work has as yet been undertaken however to explore the potential and limitations of beta-Ga2O3 for such radio frequency (RF), high power applications.

This work will investigate the potential of beta-Ga2O3 for the production of electronic devices for both high power and high frequency operation. We will undertake a feasibility study utilising commercially sourced beta-Ga2O3 substrates to better understand their physical, chemical and electronic structure and the associated charge transport and electronic device production potential. Utilising previously established expertise in the development of WBG and UWBG device technologies, processing protocols for the creation of beta-Ga2O3 devices such as field effect transistors will be established. Devices with varying geometries (which strongly impact both high power and high frequency operation) will be investigated to maximise understanding of device operation and performance potential. Moving forward, the outputs of this work will be used to identify an ongoing research strategy for beta-Ga2O3 based electronics within the UK in partnership with national academic groups and industry active in complementary areas of WBG and UWBG research.

Potential Impact:
The proposed work aims to evaluate a new semiconductor material system with the unique potential to deliver advanced high power and high frequency system performance in a scalable and cost-competitive technology. Technology areas that would benefit from this work include super-high voltage components required for future electric automotive vehicles and electricity distribution smart grids; advanced electrical systems for future manned and unmanned space and extra-terrestrial exploration; high temperature electronic systems for oil and gas drilling, aerospace and defence applications; next generation communication and radar systems. This work will therefore directly aid to address several societal challenges outlined in the EPSRC's delivery plan e.g. "Energy security and efficiency" and "Reliable infrastructure". The work also strongly aligns with the EPSRC priority areas "Materials For Energy Applications" and "RF & Microwave Devices".