Structural and luminescence characteristics of cycled submonolayer InAs/GaAs quantum dots with room-temperature emission at 1.3 μm

Abstract

Quantum dots were grown by molecular beam epitaxy on GaAs substrates using a cycled submonolayer InAs/GaAs deposition technique. Their structural and luminescence characteristics have been compared with conventional self-organized dots. The room-temperature luminescence spectra are characterized by a ground state transition at 1.3 μm and additional transitions corresponding to excited states. Cross-sectional transmission electron microscopy indicates that no dislocations are formed if the total InAs thickness is less than 5–6 monolayers. Temperature dependence of the photoluminescence indicates that both types of quantum dots may have nonradiative defects, caused by segregation and related phenomena.