The effects of ultraviolet (UV) light Irradiation on the conducting properties of SnO2-x films are studied at room temperature (RT). Large enhancements in conductivity up to 4 orders of magnitude are observed in vacuum for almost insulating films containing small amounts of oxygen vacancies. It Is ascribed to the desorption of negatively-charged oxygen species from the grain boundary, which dramatically enhances the mobility of electron carriers already present in the grains through the reduction of potential barriers at the boundary. The lowresistive state induced by light irradiation recovers to the original insulating state by exposing oxygen gas at RT.
ASJC Scopus subject areas
- Physics and Astronomy(all)