Abstract
We report efficient low-temperature anti-Stokes photoluminescence (upconverted photoluminescence= UPL) at resonant excitation of coupled silicon nanocrystals (NCs) in porous silicon (PSi). This photoluminescence is absent in strongly oxidized porous silicon and oxidized silicon nanocrystals. The UPL is a result of resonant excitation of electron-hole (e-h) pairs spatially separated in neighboring crystals with different band-gap. II is generated by the excitation of a second e-h pair in the larger of the two crystals and Anger ejection of a carrier into the smaller one, with the larger band-gap. (C) 2001 Elsevier Science B.V. All rights reserved.
Original language | English |
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Pages (from-to) | 135-139 |
Number of pages | 5 |
Journal | Optical Materials |
Volume | 17 Jun-Jul |
Issue number | 1-2 |
Publication status | Published - 2001 |