This invention covers a new material for the back electrode contact in CdS/CdTe photovoltaic cells to enable a continuous in-line physical vapor deposition process for all cell layers. Applications: This is an improved structure for the CdS/CdTe class of thin film semiconductor solar cell which is used in roof-top and ground-mounted solar electrical power arrays for residential and small commercial applications and for grid-connected utility systems.
(1) The novel back electrode interface material enables more cost-effective manufacturing using a continuous in-line physical vapor deposition process for all the cell layers eliminating the solution processing step now used commercially to create the back electrode contact. (2) The novel back electrode interface material may provide further cost reduction by enabling a thinner CdTe layer and lower cost back electrode materials. (3) A low resistance contact is provided for to the p-CdTe layer which enables a module efficiency of 9% to 12% which is comparable to that obtained in current commercial CdTe photovoltaic cells from such vendors as First Solar. (4) This back electrode contact layer is compatible with both conventional glass and flexible substrates and is robust to flexing.