Photoluminescence study of Nd:YAG laser-etched silicon

Photoluminescence (PL) spectra of porous silicon (PS) samples fabricated with laser-induced etching (LIE) in HF acid are analyzed using a quantum confinement model with an assumption that porous silicon consists of a distribution of nanocrystallites corresponding to the Gaussian function. The mean nanocrystallite size and size distribution parameters are studied here as a function of the laser power density and irradiation time during laser-induced etching. The photoluminescence peak position energy is found to vary between 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 optimizing laser parameters in the etching process.