The wide bandgap semiconductors have the potential for having better power conversion efficiency and higher current handling capability. Among various wide bandgap semiconductors, b-Ga2O3 has a stable thermodynamic property with a large bandgap and high electron mobility which makes it an attractive semiconductor candidate for next-generation power electronics and optoelectronics. Despite promising material property of b-Ga2O3, two well-known deficiencies of b-Ga2O3, namely, the poor thermal conductivity and the lack of efficient p-type dopant largely prohibit the use of b-Ga2O3 toward wider spectrum power electronics. This proposal aims to address the unipolar doping challenge and poor thermal property of n-type b-Ga2O3 by heterogeneously integrating with p-type single crystalline diamond, which allows us to bond two dissimilar semiconductors without restricted by lattice constants of b-Ga2O3 and diamond. To create a novel n-type b-Ga2O3 and p-type diamond heterojunction, an ultra-thin form of semiconductor, also called semiconductor nanomembranes, will be used. Building upon this, the specific objective of the proposed project is to realize the new class of ultra-wide bandgap high power heterojunction bipolar transistors based on the multiple p-n junctions using p-type diamond nanomembrane and n-type b-Ga2O3 nanomembrane. The outcome of the proposed research will result in the development of high power electronic devices operating at higher power density level, which could revolutionize power distribution and conditioning, allow for a more versatile and stable power system with the improved power conversion or handling efficiencies toward future high-power electronics.
The proposed research aims to develop the new class of ultra-wide bandgap high power device based on the novel heterogeneous integration method. It will provide a comprehensive solution to develop a completely new class of highly efficient high-power switches which will lead to greatly enhanced switching performance metrics over that of today's power electronics. We expect that upon the success of this project, the related commercialization will experience a significant change toward employing our new heterojunction technology in many possible ways. This research will also help train the next generation of scientists/engineers who will work at the interface of physics, materials science, and engineering. During the project period, various educational and outreach activities will be given at several different levels, including graduate, undergraduate, K-12, and community. The vision of this program is to provide these students with hands-on, interdisciplinary experiences in computational simulation and experimental research topics for tackling current technological and societal challenges. The project will provide excellent opportunities to educate and train undergraduate and graduate students, who will be exposed to various interdisciplinary fields of materials science and semiconductor nanoscience.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
