کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1546998 | 997627 | 2010 | 4 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Photoluminescence properties of exciton–exciton scattering in a GaAs/AlAs multiple quantum well Photoluminescence properties of exciton–exciton scattering in a GaAs/AlAs multiple quantum well](/preview/png/1546998.png)
We report on the photoluminescence (PL) properties of a GaAs (20 nm)/AlAs (20 nm) multiple quantum well under high-density-excitation conditions at excitation energies near the fundamental exciton energies. The biexciton-PL band is dominant in a relatively low-excitation-power region. The PL originating from exciton–exciton scattering, the so-called P emission, suddenly appears with an increase in excitation power. The excitation-energy dependence of the intensity of the P-PL band indicates that the excitation energy higher than the fundamental heavy-hole exciton by the energy of the longitudinal optical (LO) phonon is the most efficient for the P PL. This suggests that the LO-phonon scattering plays an important role in the relaxation process of excitons leading to the P PL. The appearance of the P-PL band remarkably suppresses the intensity of the biexciton-PL band; namely, the exciton–exciton scattering process prevents the formation of biexcitons. Furthermore, we have confirmed the existence of optical gain due to the exciton–exciton scattering process with use of a variable-stripe-length method.
Journal: Physica E: Low-dimensional Systems and Nanostructures - Volume 42, Issue 10, September 2010, Pages 2644–2647