All-solution-processed CIS solar cells based on electrodeposited ZnO nanopillars

One-dimensional (1D)-nanostructured CuInS₂ (CIS) solar cells based on electrodeposited ZnO nanopillar arrays have been prepared by an all-solution process. The electrodeposition of ZnO is performed galvanostatically from Zn(NO₃)₂ aqueous solution. CIS is deposited on the ZnO by dip-coating a molecular-based organic solution and subsequent heating in an Ar atmosphere. This in-situ CIS synthesis method offers good penetration behavior into the gap between ZnO nanopillars and the formation of compact CIS nanocrystal layers without dissolution of ZnO. Characterization of the CIS layer is carried out with an X-ray diffractometer, field-emission scanning electron microscope, and UV-vis-NIR absorption spectrophotometer. To improve the photovoltaic performance, the introduction of a buffer layer and/or an electron blocking layer into the ZnO/CIS interface and the CIS surface, respectively, is also studied by using solution processes.