Dynamics of charge carrier energy relaxation and recombination in undoped and P-doped GaAs quantum wells

✍ Scribed by J. Christen; D. Bimberg; A. Steckenborn; G. Weimann; W. Schlapp

• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 423 KB
• Volume: 2
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1016/0749-6036(86)90028-5

✦ Synopsis

Character and dynamics of charge carrier energy relaxation and recombination are disclosed in detail by tlme delayed and time resolved cathodoluminescence experiments of undoped and doped GaAs/Gao.6AI 0 4As multiple quantum wells with thickness 5 nm < L z < 11 nm. At all temperatures up to room temperature the luminescence in doped and undoped samples is unambigously identified to be of excitonic origin: The luminescence decays exponentially and shows no contributions of blmolecular e-h-recombination. The excltonlc recombination probability is found to increase up to one order of magnitude as compared to 3D material, it also increases strongly wlth decreasing temperature, p-doping induces a further increase without opening undesired impurity assisted recombination channels: Enhanced occupation of several hole subbands can increase the effect of several independent excitonic recombination channels, thus reducing the effective lifetime. Excitation intensity dependent experiments show electron and hole relaxation from higher subbands to the lower ones.