Stable CdTe thin film solar cells with a MoO_x back-contact buffer layer

MoO_x thin films were employed as a buffer layer in the back contact of CdTe solar cells. A monograined CdS layer was employed as the window layer to reduce light absorption. The insertion of a MoO_x buffer layer in the back contact greatly reduced the Schottky barrier leading to increased fill factor and open-circuit voltage. A CdTe solar cell, with an efficiency as high as 14.2%, was fabricated. The use of a MoO_x buffer layer made it possible to fabricate high-efficient CdTe solar cell with much less Cu in the back contact, thus greatly enhancing the cell stability.