Properties of real surface of CdS thin films

Using the method of oxygen chemisorption the composition of CdSe crystallite real surface has been determined. The nature and concentration change of surface electrically active defects as well as annealing effect on adsorptional ability of thin CdSe films and form of oxygen chemisorption on their surface are investigated. Two types of the main active centres have been detected on the surface of cadmium selenide layers: selenium vacancies and excessive cadmium atoms. Absorption ability of samples at 473 K is determined only by the type and concentration of the surface adsorption centres. At room temperature adsorption ability depends on free electron concentration in the volume of crystallites and the height of potential barrier on their surface. In both cases the main form of oxygen chemisorption is conditioned by the nature of the main adsorption centre