Carrier dynamics in CaAs-Al0.46Ga0.54As superlattice structure grown by molecular beam epitaxy

Molecular beam epitaxy (MBE) grown GaAs-Al0.46Ga0.54As superlattice (SL) st ructures containing one thicker single quantum well (SQW) are investigated with use of time-integrated and time-resolved photoluminescence in the temp erature range 10-300 K. Analysing the temperature dependence of the integra ted PL intensity, we observe thermally activated carrier transfer from the SL to the SQW, for temperature higher than 70 K. Both radiative and nonradi ative recombination times have been extracted from the combined measurement s of the PL decay time and the PL-integrated intensity, The nonradiative pr ocesses in the SL have been found to play an important role and become domi nant for T greater than or equal to 70 K. Due to the carrier transfer from the SL to the SQW, the radiative time in the SQW dominates the recombinatio n up to 220 K. We believe this heterostructure for the development of quant um-well lasers operating at room temperature to be applicable. (C) 2001 Els evier Science B.V. All rights reserved.