Green light emission from selectively grown InGaN multiple quantum well stripes oriented along [11-20] direction

Abstract

InGaN multiple quantum wells (MQWs) with green light emission have been grown on GaN stripes oriented along the [11-20] direction by selective metal-organic vapor phase epitaxy (MOVPE). Several different window widths were designed in the SiO₂ mask. Completed pyramidal InGaN stripes with flat and smooth {1-101} sidewall were produced on 2-μm windows while trapezoidal stripes with both {1-101} sidewall and (0001) top surface were obtained on the 5-μm windows. The former has uniform CL emissions at 500 nm on the {1-101} sidewall and at 550 nm on the narrow ridge. The latter exhibits similar CL emissions at 500 nm on the sidewall and at 570 nm on the top surface. These wavelength shifts relative to the CL spectrum peak (450 nm) from the reference region are attributed to thickness enhancement and indium enrichment in selective MOVPE. The short-wavelength shoulder near 500 nm in the spectrum from the ridge of the completed pyramidal strip is attributed to overlapping excitation of the sidewall by the SEM incident beam.