PHOTOLUMINESCENCE AND PHOTOEXCITATION SPECTRA OF POROUS SILICON SUBJECTED TO ANODIC-OXIDATION AND ETCHING

The photoluminescence and photoexcitation spectra of porous silicon fi lms with an initial porosity of 50-60%, produced on single crystals of p-type silicon and subjected to anodic oxidation and chemical etching , are studied, The existence of an amorphous phase in the etched porou s silicon is found nor to affect the photoluminescence spectrum of por ous silicon. Features of the photoexcitation spectra before and after etching, as well as the evolution of the photoluminescence and photoex citation spectra after etching, can be interpreted in terms of a unifo rm quantization model that includes elastic stresses in the silicon cr ystals of the porous silicon. (C) 1997 American Institute of Physics.