Photoluminescence from trapped excitons in quantum well structures
Xiaohan Liu; Daming Huang; Zuimin Jiang; Xuekun Lu; Xiangjiu Zhang; Xun Wang; Xiaohan Liu; Surface Physics Laboratory and Fudan T D Lee Physics Laboratory, Fudan University, Shanghai 200433, People's Republic of China; Daming Huang; Surface Physics Laboratory and Fudan T D Lee Physics Laboratory, Fudan University, Shanghai 200433, People's Republic of China; Zuimin Jiang; Surface Physics Laboratory and Fudan T D Lee Physics Laboratory, Fudan University, Shanghai 200433, People's Republic of China; Xuekun Lu; Surface Physics Laboratory and Fudan T D Lee Physics Laboratory, Fudan University, Shanghai 200433, People's Republic of China; Xiangjiu Zhang; Surface Physics Laboratory and Fudan T D Lee Physics Laboratory, Fudan University, Shanghai 200433, People's Republic of China; Xun Wang; Surface Physics Laboratory and Fudan T D Lee Physics Laboratory, Fudan University, Shanghai 200433, People's Republic of China
Журнал:
Journal of Physics: Condensed Matter
Дата:
1996-05-20
Аннотация:
Photoluminescence spectra from quantum well structures grown at high temperatures are investigated. The luminescence properties are found to be very different from those of free excitons. To describe correctly the spectral lineshape, the radiative recombination from excitons trapped on the local potential fluctuations in quantum wells must be considered. At low sample temperatures, the luminescence is mainly from the trapped excitons. With increasing temperature, trapped excitons are thermally activated into free excitons and luminescence peaks shift to higher energies. By comparing measured spectra with the calculated spectra, the trap density and the trap energy are derived. The origin of the trap and its relation with the crystal growth are discussed.
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