Current Research Areas

Heterogeneous III-V on Si Integration Platform

Our group is interested in lattice mismatched growth of III-V compound semiconductors on silicon by metal-organic chemical vapor deposition (MOCVD) for heterogeneous integration. This involves developing a fundamental understanding of the nucleation process, crystal lattice engineering, defect study, and advanced materials characterization from macro- to nanometer-scale. We have explored a variety of techniques, including metamorphic buffer layer approach, nano-scale pattered growth, aspect ratio trapping, interfacial misfit (IMF) array, epitaxial lateral overgrowth, and so on. Oftentimes, these methods are combined with low-dimensional structures like quantum dots, quantum wires and nano-ridges so as to leverage the inherent crystallographic geometry for defect trapping and filtering. By establishing a monolithic III-V on Si platform with a broad spectrum of materials, we are actively engaged in fabricating emerging devices, developing new functionalities, and integrating heterogeneous device technologies.

Details >>

III-V Quantum Dot Lasers on Silicon

Miniaturized laser sources can benefit a wide variety of applications ranging from on-chip optical communications and data processing, to biological sensing. There is a tremendous interest in integrating these lasers with rapidly advancing silicon photonics, aiming to provide the combined strength of the optoelectronic integrated circuits and existing large-volume, low-cost silicon-based manufacturing foundries. Using III-V quantum dots as the active medium has been proven to lower power consumption and improve device temperature stability.

Details >>

III-Nitride Power Electronics

Featuring a wide band gap and large critical electric field, III-nitride based electron devices are emerging for next generation energy-efficient power conversion applications. Our group is interested in developing cost-effective high-performance III-nitride power transistors and diodes for high-voltage switching applications. This covers heterogeneous epitaxy of high-quality III-nitride materials on large-scale silicon substrates via MOCVD, design of proper device structures using advanced semiconductor device physics, their physical realization through hand-on processes with state-of-the-art clean-room fabrication facilities and advanced characterization facilities. With particular interest in developing cutting-edge high-performance enhancement-mode GaN transistors, we have explored a wide range of approaches including recess-free barrier engineering using selective area regrowth technique, p-type GaN gate technology, and vertical MOSFET structure. Through the establishment of high-performance GaN transistors and diodes, we are aiming at deepening the understanding of the III-nitride electron device physics, uncovering the full potential of III-nitride materials, and facilitating the wide employments of III-nitride devices for future power applications.

Details >>

III-Nitride Micro-Display Technology

Micro-display technology is an essential part to build up wearable/portable electronics including smart phones, smart watches, fitness wristbands, virtual reality (VR) and augmented reality (AR) glasses, which have become ubiquitous in our daily lives. InGaN/GaN micro-LEDs technology is a promising solution to realize micro-display, bringing advantages such as high brightness, high efficiency, low power consumption, and long lifetime.

Details >>