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

Tungsten doped stannic oxide transparent conductive thin films (W-doped SnO2) 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 SnO2 begins to transform into crystalline SnO2 when annealed at 300 degrees C. The resistivity of 2 at.% W-doped SnO2 achieves 2.94 x 10(-2) Omega cm annealed in air at 500 degrees C. The transmittance of W-doped SnO2 films (around 87%) is better than that of pure SnO2 films (around 83%) in visible range contrasted with blank quartz glass. The optical band gaps of both doped and pure SnO2 films are over 3.7 eV.