10.1021/jp5004209.s001 Eran Edri Eran Edri Nir Kedem Nir Kedem Hagai Cohen Hagai Cohen Piers Barnes Piers Barnes Gary Hodes Gary Hodes Higher Open Circuit Voltage and Reduced UV-Induced Reverse Current in ZnO-Based Solar Cells by a Chemically Modified Blocking Layer American Chemical Society 2014 FTO substrate ZnO rods ZnO layer Sb ions uniform layer Open Circuit Voltage shunt resistance leakage glass substrate ZnO nanorod growth ZnO chemical deposition bath hole conductor CuSCN hole conductor UV light 2014-07-31 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Higher_Open_Circuit_Voltage_and_Reduced_UV_Induced_Reverse_Current_in_ZnO_Based_Solar_Cells_by_a_Chemically_Modified_Blocking_Layer/2269855 Solid-state semiconductor-sensitized solar cells require a thin, dense hole-blocking layer at the conducting glass substrate (F-doped tin oxide (FTO)) to prevent shorting beween the FTO and hole conductor. We found that by adding a small amount of Sb ions to a ZnO chemical deposition bath a thin (few tens of nanometers thick) dense and uniform layer of Sb-incorporated ZnO forms. Here we investigate the electronic properties of this layer in comparison to the continuous ZnO layer at the base of the ZnO rods formed in the standard preparation. Devices incorporating the Sb-incorporated dense layer followed by a standard ZnO nanorod growth, onto which CdS or CdSe was grown followed by a CuSCN hole conductor, showed 100–200 mV higher photovoltage together with occasional improvement in the short-circuit current. Electrochemical and electrical measurements indicated complete coverage of the FTO substrate by both preparations; however, the shunt resistance (resistance to a reverse leakage current) in the cells (and films) made using the Sb-incorporated ZnO layer is dramatically increased. Using bias-dependent incident photon-to-electron conversion efficiency studies, we found that an increased dark or leakage current develops in the cell on illumination with UV light together with application of a forward bias. This can be explained by the presence of a “Schottky junction” at the FTO\ZnO interface. This increased leakage current is significantly larger in cells without the Sb-incorporated ZnO compact layer.