A review on GaN-based two-terminal devices grown on Si substrates

Abstract

Gallium nitride (GaN) based two-terminal devices, such as Schottky barrier diodes (SBDs), p-i-n diodes and light-emitting diodes (LEDs) are essential components for power conversion and optoelectronic applications, due to superior material properties including wide band gap (3.4 eV), high electron velocity, and large critical breakdown field. This article reviews the recent progress made in GaN two-terminal devices grown on lattice-mismatched Si substrates. Advances in material epitaxy, device design, and fabrication technology are illustrated for GaN diodes. A comprehensive overview of static and dynamic characteristics for both quasi- and fully-vertical p-i-n diodes are presented. With the developments of device design and processing technologies, various cracks-free LEDs-on-Si are achieved with wide spectrum coverage and improved efficiency. Nanowire LEDs and micro-LED display using GaN-on-Si epitaxy are also discussed. In addition, monolithic integration of GaN diodes with transistors as well as photodetectors enables creation of compact components with much reduced parasitic and small footprint, unlocking great potential of GaN-based device technology for versatile functionalities.