Influence of Functional Layers Thickness on CdTe Based Flexible Solar Cells Efficiency

In order to develop a constructive solution of flexible high efficiency thin-film solar cells based on the CdS/CdTe system adapted for the installation of a solar battery from such solar cells directly onto the standard solar thermal collector plate the serie of flexible solar cel cells samples with various thickness of functional layers it has been manufactured. The research of solar cells test samples carried out by optical methods and by measurement and subsequent analytical processing of illuminated current-voltage characteristics. It has been established that the absorption coefficient of flexible CdS/CdTe based solar cells in the visible range is 105 cm-1, and the reflection coefficient in the infrared spectrum region does not exceed 7-8 % which allows excluding absorber with a selective coating from collector because its function will perform directly by such solar cell. It has been shown that, due to a significant reduction of substrate weight for flexible solar cells, it was possible to achieve specific power values up to 2.0 kW/kg.