Molecular beam epitaxial growth and characterization of InGaN/GaN dot-in-a-wire nanoscale heterostructures: toward ultrahigh efficiency phosphor-free white light emitting diodes

摘要

One of the grand challenges for future solid state lighting is the development of high efficiency, phosphor-free white light emitting diodes (LEDs). In this context, we have investigated the molecular beam epitaxial growth and characterization of nanowire LEDs on Si, wherein intrinsic white-light emission is achieved by incorporating self-organized InGaN quantum dots in defect-free GaN nanowires on a single chip. We have further demonstrated that, with the incorporation of p-type modulation doping and AlGaN electron blocking layer, InGaN/GaN dot-in-a-wire white LEDs can exhibit nearly zero efficiency droop and significantly enhanced internal quantum efficiency (up to -57%) at room-temperature.