Etching depth dependence of emission properties from InGaN/GaN light emitting diodes with nanohole arrays: Analysis of strain relaxation and surface states

The effects etching depths of nanohole arrays close to or penetrate the quantum well structures are studied. Our results suggest that when the hole depth is close to the quantum well region, the surface states pinning reduces the band bending and leads to a blue shift of the emission spectrum. When the hole penetrates the quantum well region, similar effects are observed but are due to the strain relaxation in the quantum well.