Green-amber emission from high indium content InGaN quantum wells improved by interface modification of semipolar (112) GaN templates

Abstract

Semipolar (112) GaN templates are improved by interface modification and employed as growth templates for green-amber-emitting high indium content InGaN/GaN quantum wells (QWs). The interface modification is realized by high-temperature annealing of an inserted low-temperature GaN layer, which enhances adatom diffusion and site-selectively blocks defects for interface-modified GaN templates. The luminescence properties of the InGaN/GaN QWs grown on the semipolar GaN templates are significantly enhanced by the interface modification. Green-amber emission with double peaks at 520 and 600 nm is observed for the InGaN/GaN QWs grown on the interface-modified semipolar GaN templates and is attributed to a) improvement in overlapping of the electron and hole wave functions due to weak polarization fields for growth along (112), b) enhancement in interband transitions involving the excited quantized carrier states, and c) reduction in electron loss at high injection currents due to reduction of threading defect density in the interface-modified semipolar GaN templates.