Relaxation of photoconductivity in nanocrystalline indium oxide

Abstract

Photoelectric properties of nanocrystalline indium oxide synthesized by the sol-gel method with nanocrystal sizes of 7-20 nm have been studied. An increase in the conductance by UV light illumination of several orders of magnitude and the retention of this high conducting state after the light is switched off is revealed. The kinetics of photoconductivity decay in air, vacuum, and argon at room temperature is studied; it is found that the photoconductivity decay is described by an expanded exponent. A conclusion about the determining role of oxygen molecules in the phenomenon of residual photoconductivity is made. A model is proposed which explains permanent photoconductivity decay in nanocrystalline indium oxide. A correlation between structural and photoelectric features in the object under study is found.