Stimulated emission from optically pumped GaN quantum dots

Abstract

Stimulated emission was observed from optically pumped GaN quantum dots in an AlxGa1−xN separate confinement heterostructure fabricated on 6H-SiC(0001) substrate by metal organic chemical vapor deposition. Nanostructural GaN quantum dots, with an average size of ∼10 nm width, ∼1–2 nm height, and density of ∼1011 cm−2, were self-assembled on the AlxGa1−xN cladding layer surface. The stimulated emission peak was observed at ∼3.48 eV, which is ∼50 meV lower than that of spontaneous emission. The excitation power dependence on the emission intensity clearly indicates threshold pump power density of 0.75 MW/cm2 for the onset of stimulated emission.