Room-temperature stimulated emission in GaN/AlGaN separate confinement heterostructures grown by molecular beam epitaxy

Abstract

Strong near-ultraviolet stimulated emission was observed at room temperature in GaN/AlGaN separate confinement heterostructures (SCH) grown by molecular beam epitaxy (MBE) on sapphire substrates. The MBE grown GaN/AlGaN SCH samples exhibited stimulated emission threshold pumping powers as low as 90 kW/cm2 at room temperature under the excitation of a frequency-tunable nanosecond laser system with a side-pumping configuration. This represents an order of magnitude reduction over bulklike GaN. Our results suggest that the carrier confinement and waveguiding effects of the SCH samples result in a substantial decrease in the stimulated emission threshold.