Photoluminescence study of Nd : YAG laser-etched silicon

Photoluminescence (PL) spectra of porous silicon (PS) samples fabricated wi th laser-induced etching (LIE) in HF acid are analyzed using a quantum conf inement model with an assumption that porous silicon consists of a distribu tion of nanocrystallites corresponding to the Gaussian function. The mean n anocrystallite size and size distribution parameters are studied here as a function of the laser power density and irradiation time during laser-induc ed etching. The photoluminescence peak position energy is found to vary bet ween 1.8 and 2 eV as the laser power density or irradiation time of the Nd: YAG laser is varied. Furthermore, the study helps in gaining fresh insight into maximizing the photoluminescence yields from porous silicon by optimiz ing laser parameters in the etching process. (C) 2001 Published by Elsevier Science B.V.