Green-emitting cubic GaN/In0.16Ga0.84N/GaN quantum well with 32% internal quantum efficiency at room temperature

Abstract

Structural and optical properties of a green-emitting cubic (i.e., zinc blende) GaN/In0.16Ga0.84N/GaN single quantum well structure are reported. The active layer is grown on a phase-pure (i.e., 100%) cubic GaN enabled on a 1 × 1 cm2 U-grooved silicon (100) through aspect ratio phase trapping. Energy dispersive x-ray spectroscopy combined with room temperature cathodoluminescence reveals 522 nm green light emission at room temperature with only 16.0% ± 1.6% of indium content, which is ∼30% less than the amount of indium needed in a traditional green-emitting hexagonal (i.e., wurtzite) well. Temperature-dependent behavior of the green emission, such as activation energy, s-shaped peak energy shift, and linewidth, is reported. Cathodoluminescence at 8 and 300 K reveals an internal quantum efficiency of 32.0% ± 0.6%, which is higher than any reported value for cubic wells. Overall, phase-pure cubic active layers on phase transition cubic GaN are shown to be promising for green and longer wavelength emitters.