Electrically Driven Single Pyramid InGaN/GaN Micro Light-Emitting Diode Grown on Silicon Substrate

Abstract

Electrically driven single-pyramid InGaN/GaN micro light-emitting diode ( $\mu$ -LED) on silicon substrate has been fabricated and investigated. The $\mu$ -LED exhibits a typical p-n diode behavior with a turn-on voltage of 2.5 V and realizes an efficient electroluminescence (EL) under an ultra-small injection current (3 $\mu$ A). An excellent EL pattern with a high-brightness spot at apex, a hexagonal blue ring around the base of pyramid, and six bright spots at the corners of pyramid base was observed. EL wavelength centered at about 450 nm, and a slight peak shift was found as the injection current increased from 100 to 1000 $\mu$ A. The small magnitude of spectral shift is attributed to the growth of multiple quantum wells on semi-polar GaN pyramid side facets and its accompanied reduction of the quantum-confined Stark effect. The $\mu$ -LED has the promising potential for applying in micro display and electrically driven single photon emitter.