INVESTIGATION OF A SUITABLE BACK CONTACT FOR CdTe/CdS SOLAR CELLS PREPARED IN THE SUBSTRATE CONFIGURATION

Several attempts in order to prepare a suitable back contact to be used for CdTe/CdS solar cells in thesubstrate configuration have been made. Excluding the use of metallic elements which can diffuse to the junction, wefound a specific configuration as a possible candidate for a stable and not rectifying contact.This configuration consists in the deposition by sputtering of a stack of layers namely 0.5μm of Mo followed by10nm of Cu, 10nm of Ag and 1μm of ZnTe. This type of contact gives the possibility to prepare CdTe/CdS solar cellsin the substrate configuration with an efficiency around 7%. By changing the parameters of preparation of the solarcells, we believe, the efficiency can be increased up to 10% or more.