InGaN/GaN/AlGaN-based laser diodes with cleaved facets grown on GaN substrates

Abstract

After obtaining an epitaxially laterally overgrown GaN on sapphire by the metalorganic chemical vapor deposition method, GaN growth was continued up to a thickness of 200 μm by a hydride vapor phase epitaxy method. The InGaN multi-quantum-well-structure laser diode (LD) was grown on a free-standing GaN substrate, which was obtained by removing the sapphire substrate. The LDs with cleaved mirror facets showed an output power as high as 160 mW under room-temperature continuous-wave (CW) operation. The fundamental transverse mode was observed up to an output power of 80 mW. The lifetime of the LDs at a constant output power of 5 mW was about 180 h under CW operation at an ambient temperature of 50 °C, due to a high threshold current density of 14 kA/cm2.