Molybdenum Oxide and Molybdenum Nitride Back Contacts for Thin-Film CdTe Solar Cells

In thin-film CdTe solar cells, a high quality back contact is essential for high voltage and fill factor. Properties such as a high work function, stability to air and moisture, and an ohmic contact to the CdTe interface are important considerations. MoO x and MoN x thin films are promising alternative back contacts. Films were deposited with varying composition via DC reactive sputter deposition. Thin film properties were measured through characterization techniques such as four-point probe measurements, profilometry measurements, Hall measurements, XPS, and GAXRD. Devices were compared between current back contact types and alternatives such as molybdenum. Experimental results for MoO x and MoN x as back contact buffer layers are discussed in detail.