Title:
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Photoluminiscence in silicon powder grown by plasma-enhanced chemical-vapour deposition: Evidence of a multistep-multiphoton excitation process
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Author:
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Roura Grabulosa, Pere; Costa i Balanzat, Josep; Sardin, Georges; Morante i Lleonart, Joan Ramon; Bertrán Serra, Enric
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Other authors:
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Universitat de Barcelona |
Abstract:
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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. |
Subject(s):
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-Matèria condensada -Propietats òptiques -Ciència dels materials -Optical properties -Materials science -Condensed matter |
Rights:
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(c) The American Physical Society, 1994
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Document type:
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Article Article - Published version |
Published by:
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The American Physical Society
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