Near-infrared intersubband emission from GaN/AlN quantum dots and quantum wells

Abstract

We report on the observation of intersubband luminescence at room temperature from GaN/AlN quantum wells and quantum dots. The quantum wells are designed to exhibit three bound states in the conduction band. Optical pumping resonant with the e1-e3 transition (λ = 0.98 μm) is used to populate the e3 excited state. Emission corresponding to the e3-e2 transition is observed peaked at 2.13 (2.3) μm for heavily (lightly) doped quantum wells. We also report on the observation of room temperature emission at λ ≈ 1.5 μm from a stack of GaN/AlN QDs through resonantly-enhanced Raman scattering involving GaN LO-phonons. The quantum dot emission is ascribed to the pz-s intraband transition of the dots. We show that this process provides room for population inversion. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.