CHARACTERIZATION OF STAIN-ETCHED POROUS SILICON

We have performed infrared absorption, continuous-wave photoluminescen ce, and nanosecond photoluminescence decay measurements to characteriz e stain-etched porous silicon. Stain-etched porous silicon samples wer e prepared by etching boron-doped crystalline silicon wafers in a solu tion of HF:HNO3:H2O with ratios of 1:5:10 by volume. The dependence of continuous-wave photoluminescence intensity upon temperature and exci tation energy has been studied. We have also investigated the dependen ce of nanosecond photoluminescence decay upon temperature, excitation energy, and emission energy. Our results suggest that the photolumines cence in stain-etched porous silicon might be due to the presence of s iloxene-type bonding configuration in an amorphous alloy of silicon, o xygen, and hydrogen.