Low-temperature preparation of ZnO thin film by atmospheric mist chemistry vapor deposition for flexible organic solar cells

A low-temperature method for the large-scale growth of ZnO thin films on flexible substrates was realized using a mist chemistry vapor deposition setup. We prepared and analyzed ZnO thin films grown on flexible PET/ITO in the temperatures range of 125–250 °C. The growth of ZnO crystallites was qualitatively investigated with respect to nucleation and substrate temperature. We observed a mixed phase in the ZnO thin films prepared at 125 and 150 °C. We conclude that the optimal substrate temperature for optimal ZnO thin films growth is between 150–200 °C. Our results show that the photovoltaic performance of an organic solar cell (OSC) is strongly dependent on both composition and morphology. To demonstrate its application on flexible organic optoelectronic devices, a large OSC with as-grown ZnO thin film as cathode buffer layer was successfully prepared.