Elemental Vapor Transport Deposition of CdSe_xTe_1-x Thin Films for n-type CdTe Solar Cells

This paper investigated the structural and electrical properties of CdSexTe1-x thin films grown by the elemental vapor transport (EVT) deposition process. The CdSexTe1-x films with various selenium concentrations were characterized in terms of optical absorption and atomic concentration, as well as morphology and crystallinity. Incorporating Se into the CdTe films results in a reduction of the bandgap which favors the generation of photocurrents at longer wavelengths. With the increase of Se composition, a phase transition from zinc blende structure to wurtzite structure occurs. SIMS measurements show a uniform distribution of Se in the CdSexTe1-x film. TRPL lifetime measurements show that the minority carrier lifetimes increase with the increase of Se composition.