Observations on the surface and bulk luminescence of porous silicon
| Autor: | T. K. Sham, D. T. Jiang, I. Coulthard, J. W. Lorimer, X. H. Feng, S. P. Frigo, Richard A. Rosenberg |
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| Rok vydání: | 1993 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 74:6335-6340 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.355156 |
| Popis: | Using the x‐ray excited optical luminescence technique, we have investigated the soft x‐ray induced photoluminescence of porous silicon in the optical region (200–900 nm) and the Si K‐edge x‐ray absorption fine structures of porous silicon in the near edge region. It is found that while porous silicon prepared at low current density (20 mA/cm2 for 20 min) exhibits a single broad luminescence band, porous silicon prepared at high current density (200 mA/cm2 for 20 min) exhibits three optical luminescence channels; i.e., in addition to the broad peak characteristic of all porous silicon, there are at least two additional optical luminescence channels at shorter wavelengths, one with modest intensity at ∼460 nm and the other a weak and very broad peak at ∼350 nm. These optical channels have been used to monitor the Si K‐edge absorption of porous silicon in the near edge structure region. Analysis of the data shows that while the band at ∼627.5 nm corresponds to the bulk emission, the other channels are of a surface origin. These observations and their implications are discussed. |
| Databáze: | OpenAIRE |
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