Imprint-induced grain growth in perovskite layers

Recent work on methyl ammonium based halide perovskites has demonstrated their capability as active materials for lasers [1] or solar cells [2]. However, solution-processed polycrystalline layers, which are obtained by spin coating, are rough and may exhibit structural defects, such as holes. It could be demonstrated that thermal nanoimprint is well suited to improve the quality of these layers. The perovskite layers are flattened, holes are less prominent and especially the crystal grains have grown. Most commonly, the quality of the layers is characterized for control purposes and with respect to the application envisaged (e.g. by XRD, PL, ASE). The physics underlying the crystal grain growth during the imprint process has not been studied yet [3].