Ultraviolet optoelectronic devices based on AlGaN-SiC platform: Towards monolithic photonics integration system

Abstract

Rapid advancement of wide-bandgap AlGaN semiconductor materials offers tremendous opportunities in the field of ultraviolet (UV) optoelectronics for a wide range of advanced applications. Additionally, SiC has large bandgap and excellent material properties, also making itself a suitable material for UV photodetection. More importantly, high-quality AlGaN alloys can be epitaxially grown on SiC substrates because of the very small lattice mismatch between them (less than 1%), which enables a possible monolithic integration of those two materials and allows us to take advantage of their material and physical properties to realize high-performance UV optoelectronics and eventually the integrated UV photonics systems. Herein, we review the recent progress in the development of UV optoelectronics based on AlGaN-SiC platform, mainly focusing on: (1) the growth strategies and material characterizations of AlGaN epilayers on SiC; (2) the fabrication and performance evaluation of UV optoelectronic devices built on the platform, including UV LEDs/lasers and UV photodetectors. Thereafter, we briefly discuss the initial efforts in the pursuit of monolithic integration of those UV optoelectronic devices. Finally, the challenges and potential advances associated with individual UV optoelectronic components as well as UV integrated photonics system on the prosperous AlGaN-SiC platform are outlined, providing insights and perspectives for possible device- and system-level innovation in future. The recent advances in the development of ultraviolet light emitters (LED, lasers) and photodetectors on the AlGaN-SiC platform are reviewed. By taking advantage of the extreme small lattice mismatch between the two wide bandgap semiconductors - AlGaN and SiC, together with their compatible physical and material properties, a monolithic ultraviolet photonics integration system can be built on the AlGaN-SiC platform. • AlGaN and SiC are recognized as two most promising wide bandgap semiconductors for UV optoelectronics applications. • AlGaN and SiC can be integrated to form AlGaN-SiC platform for the monolithic UV photonics integration system. • This review provides a comprehensive summary of the recent advancement of UV optoelectronics based on the AlGaN-SiC platform. • The outlooks and challenges in device- and system-level innovation of UV optoelectronics on AlGaN-SiC platform are discussed.