Porous silicon photoluminescence modification by surface treatments and impregnation of carbon based nanoclusters

Abstract

It has been shown that the photoluminescence (PL) intensity of a porous silicon (PS) sample, covered by a thin SiC film is six times larger compared with the initial PS subjected to rapid thermal annealing (RTA), and a strong up-shift (∼100 nm) is observed relative to the non-treated PS + SiC sample. Clustering processes with participation of SiC compounds on quantum wires cause these spectral changes. Silicon carbide and diamond-like carbon (DLC) films deposited onto PS have been used as modification and functional layers. The long-wave and short-wave region of light emission was observed after their deposition on the PS surface. The SiC film deposition leads to a decreasing of the PL intensity up to three times in the long-wave range (700 nm) compared to the initial PS, and to the appearance of high energy emission (450 nm) attributed to the emission of SiC compounds. The DLC film deposition leads to a modification of the PS properties. The result of RTA is a substantial decreasing of the PL intensity, and a considerable transformation of the spectral bands.