T. Druffel, B. Lavery
University of Louisville,
Keywords: perovskite, photovoltaic, advanced manufacturing, roll to roll, intense pulsed light
Summary:Perovskite solar cells have the possibility of becoming the next generation of industrial solar cells due to their ease of manufacturing, use of common materials, and respectable efficiencies. Since the first report of perovskite solar cells, the technology has evolved to certified power-conversion efficiencies above 20% in a span of only 5 years. The cells are based on organometal halide perovskite materials characterized by high extinction coefficients and carrier mobilities. Unlike traditional semiconductor solar cells, the perovskite solar cell is amenable to changes in the atoms of its crystal structure, which opens up opportunities for low temperature processing techniques. Most solution phase deposition techniques yield a thin film constituted by small grains, which are then relaxed using thermal or solvent extraction techniques. Although, these techniques work very well, they are limited by the low sublimation temperature of the methyl ammonium lead iodide. In this paper, we demonstrate another method to rapidly process the deposited films using intense pulsed light. The film is completely transformed from a deposited cubic structure to a smooth coating with large grain sizes. More importantly, the process occurs in less than 1 millisecond, which is encouraging for continuous manufacturing. In this talk we will describe the evolution of the thin film from deposition to device using scanning electron microscopy, X-ray diffraction, UV-Vis spectroscopy and photoluminescence. We will also demonstrate a working cell and compare to the state of the art production techniques.