Tellurium Oxide as a Back-Contact Buffer layer for CdTe Solar Cells

Tellurium oxide $(\mathbf{TeO}_{x})$ was deposited at the back of CdSeTe/CdTe substrates to create a buffer layer to reduce recombination and create a high performing dopant free cell. In these experiments we study the effects $\mathbf{TeO}_{x}$ thickness, $\mathbf{CdCl}_{2}$ treatment, and copper doping have on device performance. Current voltage measurements show efficiencies and open circuit voltages up to 17.5% and 829 mV without the use of copper doping. Furthermore, the TRPL lifetime showed a very significant increase in the absence of copper.