Resonant Tunneling Assisted Electroluminescence in InGaN/GaN Green LEDs with Nanocrater Structures

Data are presented on the resonant-tunneling-related abrupt red shift observed in the temperature-dependent electroluminescence spectra of high-brightness InGaN/GaN multi-quantum-well green LEDs. It is found that the red shift arises mostly between 120 and 150 K, and brighter LEDs yield larger red shifts. These results are well explained by the proposed nanocrater model in which a Ga-rich quantum barrier surrounds the In-rich quantum-dot-like localized state. Intensity analysis manifests that the resonant tunneling from the quantum well to the nanocraters induces such an abrupt energy shift and enhances the room-temperature emission.