Phosphor-free micro-pyramid InGaN-based white light-emitting diode with a high color rendering index on a (3-Ga2O3 substrate

We demonstrate the InGaN/GaN-based monolithic micro pyramid white (MPW) vertical LED (VLED) grown on (-201)-oriented beta-Ga2O3 substrate by selective area growth. The transmission electron microscopy (TEM) reveals an almost defect-free GaN pyramid structure on (10-11) side walls, including stacked dual-wavelength multi-quantum wells (MQWs). From the electroluminescence (EL) spectra of the fabricated MPW VLED, a white light emission with a high color rendering index (CRI) of 97.4 is achieved. Furthermore, the simulation shows that the light extraction efficiency (LEE) of the MPW VLED is at least 4 times higher compared with the conventional planar LED. These results show that the MPW VLED grown on beta-Ga2O3 has great potential for highly efficient phosphor-free white light emission. (c) 2024 Optica Publishing Group