IN-SITU ULTRAVIOLET ILLUMINATION OF POROUS SILICON DURING SCANNING-TUNNELING-MICROSCOPY

Studies of porous silicon before and during ultraviolet excitation wer e performed using scanning tunneling microscopy. Images taken during u ltraviolet excitation compared with images taken immediately prior to ultraviolet excitation show changes in the size of selective surface f eatures. There is an increase in feature height and a decrease in feat ure width between the images of nonluminescing and luminescing porous silicon. These drastic effects are a consequence of an increase in ava ilable charge carriers in porous silicon, namely, in the quantum wires . (C) 1998 American Vacuum Society.