The influence of various front contact materials on the performance of CdTe solar cells

The use of a resistive, or buffer, layer in the front contact structure of CdTe solar cells has been known to improve solar cell performance, in particular when the CdS thickness is relatively small. This paper reviews the performance of CdTe solar cells fabricated on various front contact bi-layer combinations. Conductive (low-/spl rho/) transparent oxides utilized for this work include SnO/sub 2/:F, Cd/sub 2/SnO/sub 4/ and ITO; resistive (high-/spl rho/) transparent oxides include SnO/sub 2/, In/sub 2/O/sub 3/, and Zn/sub 2/SnO/sub 4/. All high-/spl rho/ layers were found to be effective within a range of processing conditions and process/device characteristics. Buffer layers of Zn-Sn-O appear to be the most promising high-/spl rho/ films for the fabrication of CdTe cells with small CdS thickness without compromising the V/sub OC/ and FF.