Investigation of Thin Film Solar Cells on CdS/CdTe Base with Different Back Contacts

• DOI: 10.4028/www.scientific.net/ast.74.119
• Publication Date: 2010-10-27T06:18:00Z
• Authors: G. Khrypunov; A. Meriuts; H. Klochko; T. Shelest; A. Khrypunova
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

The peculiarities of photo-electric processes in thin film CdS/CdTe solar cells (SC) with different back electrodes (Cu/Au, ITO, Cu/ITO) have been studied. As it was established by capacitance – voltage (C – V) characteristics, the potential barrier heights for CdTe/Cu/Au and CdTe/ITO were 0.3 eV and 2.2 eV, respectively. The concentrations of charge carriers near back contact consisted 91020 m–3 and 21021 m–3, respectively. A high carrier concentration and high potential barrier of the ITO back contact caused the tunnel – recombination mechanism of the charge transport. The investigations of CdS/CdTe/ITO SC spectral photosensitivity testify a negative impact of the developed grain-boundary surface of the base layer on the processes of diffusion and separation of non-equilibrium current carriers generated by short-wave radiation. It is shown that the deposition of Cu nanolayer before the deposition of ITO films give stable efficiency 10 % for bifacial CdS/CdTe solar cells.