Study of the electronic and optical bonding properties of doped SnO2

Numerous metal oxide semiconductor materials were reported to be usable as semiconductor gas sensor, such as ZnO, SnO2, TiO2 and so on. These materials have non-stoichiometric structure so free electron originating from oxygen vacancies contribute to electrical conductivity. The interaction of different gas compounds with an oxide surface may lead to changes in the lattice oxygen content at the surface in addition to changes in the amount of adsorbed species. The samples of Cu doped SnO2 have been synthesized by solid-state reaction method. Some aspects of crystal structure of the compound at room temperature were studied using X-ray diffraction technique. The XRD study of the compound shows that there is a change in the crystal structure of SnO2 on substitutions of CuO. The patterns of the SnO2 sample are indexed as tetragonal perovskite type with a = 7.3928 Å, c = 5.2879 Å but on substitution of CuO the structure becomes orthorhombic with lattice constant a = 21.8594 Å, b = 5.3200 Å, c = 5.1803 Å. Several bands due to fundamentals, overtones and combination of OH, Sn–O and Sn–O–Sn entities appear in 4000–800 cm−1 range.