IIT Guwahati-Led Multi-Institutional Team Achieves Breakthrough in Ultra-Wide Bandgap Semiconductors

Researchers from the Indian Institute of Technology, Guwahati led by Dr Ankush Bag, Assistant professor, Department of Electronics and Electrical Engineering and Centre for Nanotechnology, in collaboration with IIT Mandi and Institute of Sensor and Actuator Systems, Technical University Wien, have developed a cost-effective method to grow a special semiconductor. This semiconductor has the potential to significantly enhance the efficiency of power electronics used in high-power applications such as electric vehicles, high-voltage transmission, traction, industry automation, among others. This innovation is expected to be used widely because it makes high-power devices function efficiently even at very high temperatures, such as 200 ºC.

The research team has developed an innovative and cost-effective technology to grow ultrawide bandgap semiconducting material named gallium oxide. This is achieved through a customised low-pressure chemical vapor deposition (LPCVD) system.

Emphasising on the need of this research Dr Ankush Bag, Assistant Professor, Department of Electronics and Electrical Engineering and Centre for Nanotechnology, IIT Guwahati, said, “Power Semiconductor devices are the heart of every power electronic system and function primarily as efficient switches, toggling ON and OFF to condition incoming power from grid to be used by end-user. For emerging high-power applications, there is a demand for compound semiconductor materials with an ultra-wide bandgap.”

Power electronic systems play a vital role to manage and control the flow of electricity. They are crucial for converting electrical energy from both renewable including solar and wind, and non-renewable sources including thermal power plants, into a form compatible with end-user applications in terms of voltage, current and frequency. However, there will always be some losses incurred when the electrical energy passes through a typical power electronic system. Researchers globally have been working on improving the efficiency of power electronic systems using materials like Gallium Nitride(GaN) and Silicon Carbide(SiC) but these have limitations, especially in terms of cost, for high-power applications.

Dr Ankush Bag further added, “The main challenge was to make thin and smooth films out of the material. After multiple trials and rigorous study, we optimised the gallium oxide semiconductor and incorporated it with tin to improve and modulate its conductivity. We have successfully developed a superior quality ultra-wide bandgap compound semiconductors and fabricated two terminal devices. The applications of this technology extend to electric vehicles, high voltage transmission, traction systems, and industrial automation.”

Speaking about the uniqueness of this research Dr Bag said, “A key challenge of this research was creating a Gallium oxide thin film on a sapphire substrate, deviating from the common use of Gallium oxide substrates. This shift enhances cost-effectiveness and thermal performance, addressing issues related to the expense and poor thermal conductivity of Gallium oxide substrates.”

The findings of the study have been published in multiple research papers in Journal of IEEE Transactions on Electron Devices and Thin Solid Films. The co-authors include Dr, Satinder K. Sharma and Mr. Arnab Mondal from the School of Computing and Electrical Engineering, IIT Mandi; Mr. Manoj K Yadav from Institute of Sensor and Actuator Systems, TU Wien, Vienna, Austria, and Dr. Ankush Bag, Department of Electronics and Electrical Engineering, IIT Guwahati.This pioneering research has received funding from the Science and Engineering Research Board (SERB), Department of Science and Technology, marking a significant leap forward in the field of high-power electronics.