Light-output enhancement of InGaN light emitting diodes regrown on nanoporous distributed Bragg reflector substrates

Utilising our novel wafer-scale electrochemical porosification approach which proceeds through the top surface by means of nanoscale vertical etching pathways, we have prepared full 2 inch wafers containing alternating solid GaN and nanoporous GaN (NP-GaN) layers that form distributed Bragg reflectors (DBRs), and have regrown InGaN-based light emitting diode (LED) heterostructures on these wafers. The NP-GaN DBR wafer is epi-ready and exhibits a peak reflectance of 95% at 420 nm prior to growth of the LED heterostructure. We observe a 1.8x enhancement in peak intensity of LED electroluminescence from processed devices, and delayed onset of efficiency droop with increased injection current. (C) 2019 The Japan Society of Applied Physics