Toward Energy-efficient Electronics from Ultrawide-Bandgap Semiconductors: Materials, Devices, and Application

Abstract
The next-generation power electronics is actively seeking new class of semiconductors, replacing silicon, to achieve the wider range of functionality of emerging areas, such as electric vehicles, data centers, high-speed communication, smart grids, and military technologies.
Moreover, the rise of global energy consumption and climate change have created an urgent need for efficient power devices to enable a green economy. Toward this goal, the (ultra)wide-bandgap semiconductors, with superior power handling capability, can be potential replacements of silicon for future energy-efficient electronics. Particularly, the emerging ultrawide-bandgap
(UWBG) semiconductor, β-Ga 2 O 3 , can lead a paradigm shift in high-power and harsh environment electronics with multi-kilovolt range devices of compact and lightweight designs, low-cost native substrates, and high radiation resistance. However, the early stage of β-Ga 2 O3
translates to many challenges in device design, fabrication, material quality optimization, and extreme environment tolerance.
My research focuses on the emerging (U)WBG semiconductors, bridging their material quality improvement with innovative device fabrication strategies, to adapt with the unique application challenges in high-power and extreme environment. In this presentation, I will
demonstrate my research on developing high-voltage and low-loss β-Ga 2 O 3 devices by engineering high electric field at Schottky junction and contact edges using oxidized noble metals and high permittivity dielectric field-plate. Besides, I will discuss the strategy of
developing radiation-hard β-Ga 2 O 3 power devices for space and defense electronics by addressing their degradation mechanism under heavy ion exposure. Finally, I will demonstrate my work in high-power GaN device development and advanced characterization of UWBG III-nitride semiconductors that can enhance their performance in high-voltage and optoelectronic applications.

Biography
Esmat Farzana is an Assistant Professor in the Department of Electrical and Computer
Engineering at Iowa State University (ISU). Her research lies at the intersection of device
fabrication, advanced defect characterization, and extreme environment application of
(ultra)wide-bandgap semiconductors with a focus on next-generation energy-efficient
electronics. Prior to joining ISU, she spent four years as a Postdoctoral scholar in the Materials
Department at University of California, Santa Barbara, investigating high-power and radiation-
hard device development with β-Ga 2 O 3 and III-nitrides. She received her PhD in Electrical and
Computer Engineering from The Ohio State University in 2019 where she built her expertise in
characterizing electronic properties and radiation effects in β-Ga 2 O 3 , AlInN, and GaN. She
obtained her B.Sc. in Electrical Engineering from Bangladesh University of Engineering and
Technology in 2011 and worked as a Lecturer in Ahsanullah University of Engineering and
Technology, Dhaka before starting her PhD in USA.
Her lead-author publications have been featured as Editor’s pick in IEEE Electron Device
Letters, Applied Physics Letters, and APL Materials. She was also invited by American Institute
of Physics (AIP) to be an editor of a book on β-Ga 2 O 3  material and devices. She was selected a
Rising Star in EECS in 2020.