ELECTRICAL PROPERTIES OF IN DOPED CDS THIN FILMS

Indium doped polycrystalline cadmium sulphide 〈CdS:In〉 thin films have been prepared by the spray pyrolysis technique on glass substrates in an enclosed dome. The different scattering mechanisms such as lattice, impurity and grain boundary scattering for CdS:In films are observed at low temperature, in the range of 303 to 120 K. The experimentally determined mobilities due to these scatterings are well interpreted with those of theoretically calculated mobilities. The d.c. conductivity for CdS:In films has also been studied in the same temperature region. The Mott variable range hopping conduction process followed below the temperature of 150 K. The Mott parameters such as N(E F ), R, W and α are found to be 1.26 × 1019 eV−1cm−3, 9.8 × 10−-7cm, 0.02 eV−1 and 2.38 × 106cm−1, respectively from the conductivity data.