UC Merced

Recently, the organic-inorganic perovskite solar cell has attracted great attention due to the easy processing and rapid developed power conversion efficiency. The tri-halide perovskite CH3NH3PbI3-xClx possessing excellent optical and electronic properties, such as absorption hands span the visible region, long charge carrier diffusion lengths, and appropriate direct band gap, makes them ideal active layer material for photovoltaic devices. In this thesis, electrohydrodynamic spraying is used to deposit the perovskite precursor film, where this technique takes advantages of both the solution based process and vapor deposition to form the continuous flat thin film. As for the post heating treatment to convert the precursor to final perovskite crystals, heat gun annealing is utilized for faster anneal and better morphology compared with conventional annealing process. This heat gun annealing provides sufficient energy to let the solvent evaporate and precursor crystallize in a short time. Thus the final dense uniform perovskite film with large grain size is produced by our techniques, which is a good candidate as the active layer for the high-efficiency photovoltaic devices. The results further demonstrate that our techniques are reliable highly reproducible to prepare planar organic-inorganic perovskite photovoltaic devices with efficiencies up to 16%.