Tungsten doped stannic oxide transparent conductive thin film using preoxotungstic acid dopant

Tungsten doped stannic oxide transparent conductive thin films (W-doped SnO 2 ) have been prepared via a solution process. We use stannous chloride, preoxotungstic acid (PTA), hydrogen peroxide and anhydrous ethanol to prepare precursor solution which is stable and colorless. By investigating the effects of tungsten doping ratio and annealing temperature on properties of tungsten doped stannic oxide films , it is found that the amounts of pores on surface can be reduced by increasing annealing temperature. Amorphous SnO 2 begins to transform into crystalline SnO 2 when annealed at 300 °C. The resistivity of 2 at.% W-doped SnO 2 achieves 2.94 × 10 −2  Ω cm annealed in air at 500 °C. The transmittance of W-doped SnO 2 films (around 87%) is better than that of pure SnO 2 films (around 83%) in visible range contrasted with blank quartz glass. The optical band gaps of both doped and pure SnO 2 films are over 3.7 eV.