Monolithic integration of nitride light emitting diodes and photodetectors for bi-directional optical communication

Abstract

Design and fabrication of monolithically integrated III-nitride visible light-emitting-diodes (LEDs) and ultraviolet Schottky barrier-photodetectors (SB-PDs) have been proposed and demonstrated. Responsivity up to $0.2{\mathrm{AW}}^{-1}$ at 365 nm for GaN SB-PDs has been achieved. It is shown that those UV SB-PDs were capable of sensitive UV light detection down to $7.16\times {10}^{-4}\mathrm{W}/{\mathrm{cm}}^2$ at 365 nm, whereas simultaneous operation of on-chip blue LEDs has produced negligible crosstalk at practical illumination brightness. Monolithically integrated LEDs and SB-PDs can function as transmitters to emit visible light signals, and as receivers to analyze incoming UV signals, respectively; this offers the potential of using such devices for bi-directional optical wireless communication applications.