Solar cell structures based on ZnO/CdS core-shell nanowire arrays embedded in Cu2ZnSnS4 light absorber

Cu₂ZnSnS₄ (CZTS) is a promising alternative for Cu(In, Ga)Se₂ (CIGS) absorber layer in thin film solar cells due to its earth abundant, inexpensive, non-toxic constituents and optimal material properties. In this report, CZTS based thin film and nanowire (NW) solar cells are studied by both experimental and simulation approaches. The CZTS thin films are grown using co-sputtering of Cu-Zn-Sn metallic precursors from a single target followed by sulfurization with elemental sulfur. CZTS superstrate solar cells using CdS as a buffer layer in both thin film and NW designs are fabricated. Simulation data shows that the NW structures enhance the light absorption of CZTS around the NWs due to light trapping effect, which may have significant impact on solar cell performance.