排序方式: 共有5条查询结果,搜索用时 62 毫秒
1
1.
2.
3.
The dependence of the excitonic lifetime on the well width has been studied in conventional GaAs/AlGaAs quantum wells. Two clearly different variations of the measured excitonic lifetime have been observed. For wide well widths, we find a nearly linear decrease of the lifetime with decreasing well width. However, when the well is further decreased, a saturation and even increase of the lifetime with decreeing well width are observed. The experimental data are compared with the theory of radiative excitonic recombination, and show that well width dependence of the measured photoluminescence lifetime can be attributed mainly to the change of the excitonic effective volume and the overlap integral as well. 相似文献
4.
Photoluminescence (PL) ia used to study the interface properties of GaAs/AlGaAs quan-tum well (QW) heterostructures prepared by molecular beam epitaxy with growth interrup-tion (GI). The discrete luminescence lines observed for the sample with GI are assigned to the splitting of the heavy-hole exciton associated with heterointerface islands with the lateral size greater than excjton diameter and mean height less than one monolayer, and the spectra have the Gaussian lineshapes. The results strongly support the microroughness model. We also study the temperature dependence of the exciton energies and find that excitons are localized at the interface roughness at low temperature even in the sample with GI, The lateral size of the microroughness of the GI sample is estimated to be less than 5nm from the exciton localization energy. 相似文献
5.
1