Semipolar [formula omitted] InGaN/GaN multiple quantum well optically pumped laser diodes selectively grown on Si (111) substrates

Abstract

We reported the selective area growth (SAG) of semipolar {112̅2} InGaN/GaN multiple quantum wells (MQWs) laser diodes (LDs) on the patterned GaN/AlN/Si (111) templates. For GaN (0001) on Si (111), the natural cleavage planes of GaN {11̅00} and Si {112̅} are aligned. In this work, the templates were patterned with stripe windows oriented along GaN [11̅00] direction. Utilizing a two-step SAG method, the semipolar GaN-based laser structures were successfully deposited on the inclined {112̅2} facets of the laser stripes. STEM measurements indicated the upper areas of inclined {112̅2} facets are nearly defect free due to the bending effect of TDs. The cavity facets were produced by cleaving method. Stimulated emission was achieved under optical pumping at room temperature, showing a threshold pump power density of 1.85 MW/cm2, which was attributed to the low defect and small internal field on the upper areas of semipolar {112̅2} facets selectively grown on the Si (111) substrates.