Optical Quality and Stimulated Emission of Molecular Beam Epitaxy Grown AlGaN in the Deep Ultraviolet

Abstract

In this work, the optical quality and stimulated emission of aluminum gallium nitride (AlGaN)/AlN double heterostructure grown by molecular beam epitaxy in the deep ultraviolet (UV) are reported. The room temperature internal quantum efficiency at a carrier density of 1 × 1018 cm−3 is around 12%, mainly limited by dislocations. For such as‐grown wafers, spectral narrowing and nonlinearity of the light output are measured from the wafer edge, with the transverse‐electric (TE)‐polarized component becoming dominant as the excitation increases. With cleaving, edge‐emitting lasing at 298 nm is measured, with an estimated threshold of 0.95 MW cm−2.