Ultrathin TiO<sub>2</sub> Films on ZnO Electron-Collecting Layers of Inverted Organic Solar Cell Hyun Ook Seo Sun-Young Park Won Hyun Shim Kwang-Dae Kim Kyu Hwan Lee Mi Young Jo Joo Hyun Kim Eunsongyi Lee Dong-Wook Kim Young Dok Kim Dong Chan Lim 10.1021/jp2063589.s004 https://acs.figshare.com/articles/journal_contribution/Ultrathin_TiO_sub_2_sub_Films_on_ZnO_Electron_Collecting_Layers_of_Inverted_Organic_Solar_Cell/2590831 Nanostructured ZnO thin films were fabricated on indium tin oxide (ITO) as hole-blocking and electron-collecting layers of inverted organic solar cells. In addition, TiO<sub>2</sub> thin films were deposited on ZnO surfaces using atomic layer deposition. Ultrathin TiO<sub>2</sub> layers with a mean thickness of <3 nm could enhance photovoltaic performance of the inverted organic solar cell; in particular, short-circuit current (<i>J</i><sub>sc</sub>) and power conversion efficiency (PCE) were increased by deposition of TiO<sub>2</sub> layers. A higher thickness of TiO<sub>2</sub> resulted in reduced photovoltaic performance. Studies on electronic structure using photoelectron spectroscopy showed that the TiO<sub>2</sub> layers should act as barrier for the electron-collection on ZnO. However, recombination of electrons and holes on the surface of ZnO can be quenched by TiO<sub>2</sub>, resulting in an improved efficiency of the IOSCs. It is demonstrated that atomic layer deposition with a precise control of film thickness can be of potential application for fabrication of energy devices. 2011-11-03 00:00:00 Ultrathin TiO 2 layers TiO 2 layers IOSC Ultrathin TiO 2 Films film PCE indium tin oxide TiO 2 thickness layer deposition photovoltaic performance power conversion efficiency ITO Inverted Organic Solar CellNanostructured ZnO