RECOMBINATION DYNAMICS IN ASYMMETRIC COUPLED QUANTUM WELL STRUCTURES
MAO HUI-BINGa, XU ZHONG-YINGb, SHEN XUE-CHUc
a Department of Materials Science, Fudan University, Shanghai 200433, China; b Institute of Semiconductors, Academia Sinica, Beijing 100083, China; c State Key Laboratory for Infrared Physics, Academia Sinica, Shanghai 200083, China
Abstract The time-resolved photoluminescence (PL) investigations of asymmetric coupled quantum well structures have been carried out in this paper. The experimental results show that for a wider interbarrier thickness the PL in the AlGaAs well will decay almost as a single exponential function, and for a thin interbarrier thickness the PL decay in the AlGaAs well is not a single exponential: the decay rate decreases gradually. These results indicate that when the tunneling becomes the main decay process in the AlGaAs well, the "effective mass filtering" phenomenon will be displayed in the PL decay process, which decreases the tunneling rate. At low temperature, the PL decay time increases with the increase of temperature. With further increase of temperature, the PL decay time decreases because of the increase of the tunneling rate and nonradiative recombination coefficient.
Received: 15 December 1995
Published: 20 March 1997