Improvement in spray deposition of the intrinsic ZnO window layer for chalcopyrite solar cells

Spray deposition is a non-vacuum process which allows homogeneous coating on a sub-micron level structured surface. This paper focuses on the further development of spray deposition of the `intrinsic´ (low-conducting) ZnO layer that is used predominantly to inhibit shunting in chalcopyrite thin film solar modules. Using a precursor solution of zinc acetylacetonate and an ethanol/water mix, ZnO layers can be deposited at a higher deposition rate, than previously reported by this method. The resulting films are more conductive yet the layers prove to be far superior in terms of stability under damp-heat conditions. Resulting solar cells have matching performance to solar cells prepared with the sputtered intrinsic ZnO.