Effects of Electrodeposition Conditions on Photoelectric Properties of CdSe Films

The CdSe films were formed under different electrodeposition conditions, and their stoichiometric components, donor densities and minority-carrier diffusion lengths were measured. Thereby the effects of deposition conditions on photoelectric properties of the films were studied. It was found that the CdSe film deposited at-0.685V （vs. SCE） in 0.1mol/1 CdSO₄+4 mmol/1 H₂SeO₃+0.2 mol/1 H₂SO₄ solution has higher photoelectric conversion efficiency. Increase of H₂SeO₃ concentration will cause the deposited layer to contain excess Se. Analysis of spot constituents with EDAX of scanning electron microscope showed that the deposited layers are non-uniform, and the effects of excess Se or Cd on the photoelectric properties were discussed. The optimum thickness of CdSe film was also considered in terms of light absorption amount and series resistance of photocell.