Chapters authored
Interface Engineering and Electrode Engineering for Organic Solar Cells
Interface engineering and electrode engineering play important roles in the performance improvement for organic solar cells (OSCs). We here would investigate the effect of various cathode modifying layers and ITO-free electrodes on the device performance. First, for inverted organic solar cells (IOSCs) with a poly (3-hexylthiophene-2,5-diyl):[6,6]-phenyl C61 butyric acid methyl ester blend, an aqueous solution method using low temperatures is adopted to deposit a ZnO interlayer in IOSCs. When the ZnO annealing temperature is above 80°C, the corresponding IOSCs show senior PCEs over 3.5%. Meanwhile the flexible devices based on poly(ethylene terephthalate) substrate display a PCE of 3.26% and good flexibility. Second, the performance of IOSCs based on AZO cathode and Ca modifier are studied. The resulted IOSCs with an ultrathin Ca modifier (~1 nm) could achieve a senior PCE above 3%, and highly efficient electron transport at AZO/Ca/organic interface, which obviously weakens the light soaking issue. Third, by introducing a 2 nm MoO3 interlayer for Ag anode deposition, the obtained OSCs show an improved PCE of 2.71%, and the flexible device also achieves a comparable PCE of 2.50%. All these investigations may be instructive for further improvement of device performance and the possible commercialization in the future.
Part of the book: Nanostructured Solar Cells
High-Quality Perovskite Film Preparations for Efficient Perovskite Solar Cells
Solar cells employing organolead halide perovskite films have caught tremendous attention, and their power conversion efficiencies were stunning from 3.9% to over 22% in only 6 years. Various research reports have shown that effective controls on perovskite crystallinity, homogeneity, and surface morphology are crucial to improving the power conversion efficiencies (PCE) of perovskite solar cells. Here, based on the typical one-step and two-step deposition methods, we would like to introduce the solvent treatment mechanisms of mixed-solvent-vapor annealing and polar solvent additive, investigate the growth mode and control means of perovskite films by physical characterizations, and discuss their effects on the photovoltaic performance improvements for perovskite solar cells.
Part of the book: Emerging Solar Energy Materials