Oxygen gas sensors based on thin semiconductor films

In the paper are submitted the researches of oxygen influence on electrical properties of semiconductor films. It is shown, that chemisorption-desorption processes, which take place during interaction of oxygen to a surface of a film determine features of course in them dark and photocurrents. Researches of chemisorption interaction of oxygen with semiconductors by methods of an X-ray photoelectron spectroscopy and the mass-spectrometry of thermal desorption products have shown, that there are two forms of a chemisorption oxygen: atomic and molecular. The correlation between the form of oxygen chemisorption and band energy, appropriate to it is established. It is stated a nature of centers oxygen adsorption in CdSe films. In case of the atomic form of chemisorption they are Se vacancies, and in case of the molecular form of chemisorption - excent Cd atoms. It is shown that the doping of surface by metal atoms makes possible to control adsorption sensitivity semiconductor surface to oxygen.