Research
Our research interest includes synthesizing, characterizing and engineering the properties of wide and ultrawide bandgap semiconductor materials and heterostructures to improve the performance and reliability of electronic and optoelectronic devices, understanding semiconductor device physics; design and fabrication of devices for high power and high frequency electronic and ultraviolet optoelectronic applications. We aspire to establish and direct a research endeavor that addresses specific challenges relevant to the concurrent trends of industry in semiconductor materials and device technologies. Below are some of the research domains which are of great interest to our research group.
Advancing wide and ultrawide bandgap materials epitaxy for high-power electronics: WBG and UWBG semiconductors represent an exciting and challenging new area of research in semiconductor materials, physics, devices, and applications. Because many figures-of-merit for device performance scale nonlinearly with bandgap, these semiconductors have long been known to have compelling potential advantages in high-power and RF electronics, as well as in deep-UV optoelectronics, quantum information, and extreme-environment applications. Only recently, however, have the UWBG semiconductor materials, such as AlGaN, diamond, Ga2O3 and AlGaO, advanced in maturity to the point where realizing some of their tantalizing advantages is a relatively near-term possibility. Yet, this emerging class of semiconductors presents a unique set of captivating scientific possibilities and obstacles, spanning from material properties to device functionalities. For instance, issues like limited mobility in UWBG semiconductors, the absence of thick drift layers, and the lack of shallow donors/acceptors pose intriguing puzzles. Our research group is deeply engaged in scrutinizing these challenges from both material and device perspectives. Our approach involves a blend of high-quality material synthesis and the enhancement of device performance. This includes tasks such as the design and simulation of epitaxial structures, the fabrication of test structures, their meticulous assessment for material improvement, and the refinement of regrowth processes.
Exploring the Future of Semiconductors and Devices Technology: Our research focuses on pioneering the next generation of nitride and oxide semiconducting and superconducting materials. These materials, essential for the development of cutting-edge electronic, quantum, and optical devices, bring forth unparalleled possibilities alongside complex challenges. In our work, we are interested to investigate novel materials, aiming to harness their unique properties for device applications. This includes exploring wurtzite-structure alloys with exceptional piezoelectric coefficients, investigating innovative strategies such as p-n heterojunctions to overcome obstacles in power device technologies, and exploring promising yet unexplored wide and ultra-wide bandgap semiconducting as well as superconducting materials. Collaborating with leading universities and institutions, our goal is to explore the fundamental characteristics of these materials, refining fabrication techniques to enhance stability, and ultimately harness their potential in transformative technologies for electronic and quantum devices, quantum computing, ultrafast electronics, and high-frequency communication systems.
Re-imagining the next-generation of Electronic Materials with Diverse Range of Properties: Our research comprehensively investigates the fundamental properties of materials, focusing particularly on overcoming challenges such as bandgap engineering, phase segregation, defect formation, compositional inhomogeneity, and doping of wide and ultrawide bandgap materials. Through systematic examinations of structural, optical and electrical properties, our group aims to unravel the complicacies associated with these challenges in these materials. This exploration yields invaluable insights, enabling us to fine-tune growth parameters and fabrication processes and guarantee the reliability and functionality of electronic devices.
Materials and Devices for Extreme Environments: (Ultra)wide bandgap semiconductors stand out due to their distinctive properties that are crucial for applications in the most challenging environments, such as those encountered in satellite/space exploration and nuclear fusion. These materials demonstrate remarkable resilience in the face of high radiation levels and extreme temperatures. We are interested in the development of radiation-hardened materials and devices and understanding the intricacies of radiation-induced defects from both materials and device perspectives. Leveraging the state-of-the-art facilities at the Radiation Laboratory at UMass Lowell, we look forward to conducting in-depth research to uncover the behavior of these semiconductors under extreme conditions.
