III-Nitride Ultraviolet Photodetectors

Abstract

The field of III-nitride (AlN, GaN, InN, and their solid solutions) ultraviolet (UV) photodetectors is the focus of intense research world-wide, owing to a wide range of practical device applications. This chapter describes the physical mechanisms by which nitride-based photodetectors operate, as well as the issues most pertinent to their further development. It presents a brief review of those fundamental principles of photodetector operation that are particularly pertinent to Gallium Nitride (GaN) technology. The chapter details the device fabrication techniques that has been developed and refined over the past few years. It reviews the common experimental techniques used to characterize GaN-based photodetectors. The chapter discusses the two primary device structures fabricated and characterized to date: Metal-semiconductor-metal and p-i-n photodetectors. Owing to their importance as a viable Photomultiplier tubes replacement, the chapter discusses Ill-nitride avalanche photodiodes.