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.
|Number of pages||5|
|Publication status||Published - 2001|
Diener, J., Kovalev, D., Heckler, H., Polisski, G., Kunzner, N., Koch, F., Efros, A. L., & Rosen, M. (2001). Strong low-temperature anti-Stokes photoluminescence from coupled silicon nanocrystals. Optical Materials, 17 Jun-Jul(1-2), 135-139.