ELECTROCHEMICAL DEPOSITION OF THIN ZNTE FILMS AS A CONTACT FOR CDTE SOLAR-CELLS

ZnTe films doped with Cu were deposited by an electrochemical method for the first time directly onto CdTe/CdS/ITO/glass substrates to form a low resistance contact to CdTe. The depositions were carried out in an aqueous solution of ZnCl2, TeO2 and CuCl2 or CuSO4 in which the substrate was externally short circuited to a Zn counter electrode to complete an electrochemical cell. Single phase films 50 nm to 300 nm thick were obtained for specific pH and TeO2 concentrations and bath temperature. Complexing the Cu2+ with triethanolamine (TEA) allowed reproducible deposition of p-type ZnTe:Cu films. ZnTe:Cu/CdTe/CdS solar cells fabricated using this method have achieved AM1.5 efficiencies of 8.7%.