Role of substrate temperature on the growth mechanism and physical properties of spray deposited lead oxide thin films

Thin films of lead oxide were synthesized by cost effective spray pyrolysis technique at different substrate temperatures on glass substrates. Effect of substrate temperature on the growth mechanism and physical properties of the films was investigated. All the films were polycrystalline in nature with tetragonal structure corresponding to alpha-PbO. The films coated at 225 degrees C and 275 degrees C were (1 0 1) oriented, while the films deposited at 325 degrees C and 375 degrees C were (0 0 2) oriented. Above 375 degrees C, the pure tetragonal nature deteriorated and the peaks corresponding to orthorhombic phase were observed. The band gap value was found to be in the range of 2.3 to 2.62 eV. All the films had a resistivity of the order of 10(3) ohm-cm. A minimum resistivity of 0.0191 x 10(3) ohm-cm was obtained for the film coated at 325 degrees C. The activation energy increased with increase in substrate temperature.