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

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-orga nized dots. The room-temperature luminescence spectra are characterized by a ground state transition at 1.3 mu m and additional transitions correspond ing to excited states. Cross-sectional transmission electron microscopy ind icates that no dislocations are formed if the total InAs thickness is less than 5-6 monolayers. Temperature dependence of the photoluminescence indica tes that both types of quantum dots may have nonradiative defects, caused b y segregation and related phenomena. (C) 1999 American Institute of Physics . [S0021-8979(99)07923-2].