Evidence for the Transport-Related Effects in the Photoluminescence From Porous Silicon

Authors: A.M. EVSTIGNEEV, M. Ya. VALAKH, A.V. SACHENKO, G.Yu. RUDKO, G.A. SUKACH, M.A. EVSTIGNEEV, S.V. SVECHNIKOV

Abstract: The luminescence intensity of porous silicon layers (PSLs) is investigated as a function of their thickness and temperature. For thin PSLs the emission intensity depends superlinearly on thickness and exponentially on temperature. For thick PSLs no rise in emission intensity with lowering temperature is observed. The data obtained suggest that, at room and some lower temperatures, the photocreated excitons are free to diffuse in PSL and can be rejected into the silicon substrate. This behavior may also explain some recent experimental results.

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