Structural, optical and electrical properties of In-doped Cd2SnO4 thin films by spray pyrolysis method

Preparation of highly conducting and transparent In-doped Cd2SnO4 thin film by spray pyrolysis method at a substrate temperature of 525 °C is reported. In-doping concentration is varied between 1 and 5 wt.%. The effect of In-doping on structural, optical and electrical properties was investigated using different techniques such as X-ray diffraction, atomic force microscopy, optical transmittance and Hall measurement. X-ray diffraction studies revealed that the films are polycrystalline with cubic crystal structure. The undoped and In-doped Cd2SnO4 films exhibit excellent optical transparency. The average optical transmittance is ∼87% in the visible range for 3 wt.% In-doping. Further In-doping widens the optical band gap from 2.98 ± 0.1 eV to 3.04 ± 0.1 eV. A minimum resistivity of 1.76 ± 0.2 × 10−3 Ω cm and maximum carrier concentration of 9.812 ± 0.4 × 1019 cm−3 have been achieved for 1 wt.% In-doping in Cd2SnO4 thin films.

Research highlights
► Preparation and characterization of In doped Cd2SnO4 thin films.
► In doping increases the transmittance of the films.
► For 1 wt.% In doping, a minimum resistivity of 1.76 × 10−3 Ω cm was achieved.