Transport properties of perovskite-based stannate thin films of La-doped SrSnO3

SrSnO₃ is a potential candidate for the perovskite-structured transparent electrode for many optoelectronic devices, especially for recently developed perovskite solar cells. La-doped SrSnO₃ thin films were deposited using pulsed laser deposition on SrTiO₃ (STO) substrate to study its structural and electrical properties. This study reveals that Lanthanum is a promising dopant for SrSnO₃. Results of the Rutherford backscattering experiment showed that the oxygen vacancies are increasing with strain on La doping. X-ray diffraction measurements revealed the increase in strain with La-doping which was the reason for the increase in oxygen vacancies. The charge-neutrality was maintained within the films by the reduction of Sn⁴⁺ to Sn²⁺. The coexistence of two tin charge states (4+ and 2+) facilitated the hopping mechanism of the conduction. It was observed that La-doping reduced the electrical resistivity by 7 orders of magnitude with no significant change in its structure. Results obtained from X-ray absorption spectra are also consistent with these results.