Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5491845 | Physica B: Condensed Matter | 2017 | 5 Pages |
Abstract
The Si-QDs/SiO2 multilayer films with phosphorus (P) doping have been prepared, and carrier multiplication effect of the films with and without P doping was investigated by relative quantum yield of photoluminescence (PL). The relative quantum yield of PL shows a step like increase when the excitation energy is larger than 2Eg of Si-QDs, and the carrier multiplication is caused by space-separated quantum cutting in adjacent QDs. The PL peak shifts toward high energy region after P-doping, and the PL intensity is enhanced, however, the threshold energy for carrier multiplication is decreased from 2.97 to 2.89Â eV. The results suggest that non-radiative recombination at the surface of Si-QDs is suppressed by P passivation, and radiative recombination from conduction band to surface defect level is possible. Energy transfer from hot electron-hole pair to surface defect level leads to the optical excitation of defect level, which generates an extra electron-hole pair, and carrier multiplication effect is observed in the P-doped multilayer film with lower excitation energy.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Xinzhan Wang, Yanmei Xu, Haixu Liu, Wanbing Lu, Wei Yu, Guangsheng Fu,