Photoluminescence of porous silicon stain etched and doped with erbium and ytterbium

A novel low cost process has been developed for application in porous silicon-based photodetectors and solar cells, where conventional doping processes are not affordable because of the high processing cost and technical difficulties. Ytterbium and erbium (Yb3+–Er3+) ions were introduced into luminescent porous silicon stain etched by thermal diffusion. Doping profiles were evaluated by energy-dispersive spectroscopy analysis. The visible and near-infrared photoluminescence of Yb3+–Er3+ co-doped stain-etched porous silicon layers is observed and evaluated under 980 nm pumping. Up-conversion processes that could improve the efficiency of silicon-based solar cells are detected.