CdSe : In ‐ In2 O 3 Coatings with n‐Type Conductivity Produced by Air Annealing of CdSe‐In Thin Films

Conversion of chemically deposited intrinsic CdSe thin films to n‐type coatings by a postdeposition process is described. A Cd:Se‐In thin film consisting of a CdSe thin film ∼0.15 μm thick and a thermally evaporated indium film ∼0.02 μm thick was air annealed at 325°C for 1 h. The resulting thin film coating of CdSe:In (0.15 μm)‐ (0.03 μm) exhibits a sheet resistance of 790 Ω/□ and an n‐type conductivity of ∼400 Ω −1 cm −1 for the top layer. Etching of the film with 1 M HCl for 6 h removes the superficial from the coating, and the underlying CdSe with indium doping shows a sheet resistance of 15 kΩ/□ which corresponds to electrical conductivity (n‐type) of ∼0.4 Ω −1 cm −1 . The composition of the film and its variation along the depth are established through analyses of x‐ray diffraction pattern and x‐ray fluorescence spectra as well as the photocurrent response of the annealed films recorded before and after chemical etching.