Demonstration of surface-saturation effect for porous silicon by hydrogen treatment

Porous silicon films were produced by the conventional anodization method. while a novel but inexpensive chemical treatment was used for the hydrogenation. which led to the significant enhancement of the PL efficiency at an optimum current density. At an optimum current density. PS with smooth surface morphology and uniform crystallite size was obtained while for higher current density. PS with a tough surface morphology and formation of cracks was indicated. A sharp reduction in PL intensity is observed for annealing temperatures similar to500degreesC and this coincides with the desorption of hydrogen frpm the PS surface. Here. the surface saturation by hydrogen treatment could become effective only after the removal of oxides from die surface of PS by a brief dip in Hydrofluoric acid (HF).