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

Electrically driven single-pyramid InGaN/GaN micro light-emitting diode ( μ-LED) on silicon substrate has been fabricated and investigated. The μ-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 μA). 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 μA. 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 μ-LED has the promising potential for applying in micro display and electrically driven single photon emitter.