Effects of annealing pressure for electrodeposited CuInSe₂ solar sell

As-deposited CuInSe2 films by electrodeposition are generally amorphous. A better photoelectric conversion efficiency of solar cell device should be derived from crystallized CuInSe₂ absorber layer, and also the schottky contact with the CdS layer. In this work, a high pressure atmosphere was applied during the heat treatment, which achieved level surface and better crystallization for CuInSe₂ thin films. We optimized the atomic ratio of eletrodeposited CuInSe₂ thin films, the parameters for annealing process and the fabrication of the entire device. Top view images from field-emission-scanning electron microscopy indicate well-defined grains of CuInSe₂ films. Raman spectrum results of annealed CuInSe₂ films shows the presence of CuInSe₂ phase, and no secondery phases such as Cu-Se were detected. Energy dispersive spectrometer analysis shows the composition atomic ratio of copper indium diselenide to be soichiometric. The measurement of solar simulater indicates an imrovement of conversion efficiency of CuInSe₂ solar cell after employing the high pressure annealing process.