Photoluminiscence in silicon powder grown by plasma-enhanced chemical-vapour deposition: Evidence of a multistep-multiphoton excitation process
The dynamics of the infrared photoluminescence (PL) in silicon powder grown by plasma-enhanced chemical-vapor deposition (PECVD) of silane is reported. A nonlinear dependence of PL intensity on laser power of the form I a: P" with n as high as 7 has been found, indicating a multistep-multiphoto...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1994 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/10651 |
| Acceso en línea: | https://hdl.handle.net/2445/10651 |
| Access Level: | acceso abierto |
| Palabra clave: | Matèria condensada Propietats òptiques Ciència dels materials Optical properties Materials science Condensed matter |
| Sumario: | The dynamics of the infrared photoluminescence (PL) in silicon powder grown by plasma-enhanced chemical-vapor deposition (PECVD) of silane is reported. A nonlinear dependence of PL intensity on laser power of the form I a: P" with n as high as 7 has been found, indicating a multistep-multiphoton excitation process. To confi.rm this hypothesis a very detailed theoretical and experimental analysis has been performed. As a result, the lifetimes of several levels in the excitation chain have been determined, as well as the optical cross section (u). For the slowest level u= 3 X 10- 18 cm2 and the lifetime is as long as 400 ms. As the energy of the emitted photon is smaller than that of the excitation photon, a model involving a considerable nonradiative energy relaxation, together with a tunnel effect is proposed. |
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