Photoluminescence from nano silicon materials prepared by photoelectrochemical methods

Light-emitting nano silicon materials were prepared by photoelectrochemical etching of n-type single crystal silicon in hydrofluoric acid solutions, a nd the influence of the operation parameters on the properties of the photo luminescence from n-type porous silicon was investigated. The current - pot ential characteristics as well as the chronoamperometric curves, strongly d epended on the experimental factors involved. The photoluminescence spectra depended on the applied potential, the intensity and the wavelength of the illumination, and the doping concentration of bulk silicon. When the appli ed potential and the illumination wavelength increased, the photoluminescen ce shifted to longer wavelength. However, when the HF concentration increas ed, the photoluminescence spectra changed little. Multiply peaked photolumi nescence spectra were obtained with the porous silicon produced from the si licon wafer with a low doping concentration (resistivity: 0.001 similar to 0.002 Omega .cm) in 10 % HF electrolyte solutions.