CVD patterning of lead iodide thin film and hybrid perovskite conversion

초록

Organic-inorganic hybrid perovskites (OIHPs ), i.e., such as methylammonium lead iodide perovskites (CH NH PbI ) have demonstrated distinguished optoelectronic properties for a variety of applications including photovoltaics (PV), light emitting diodes (LED), and photodetectors, etc. To this end, solution-based crystallization of OIHPs has been widely employed to prepare perovskite thin films desired for the device fabrication process. attracted interests due to their enormous potential in photovoltaics (PV) application, such as Solar cell, light emitting diodes (LED), and photodetectors. Most applications are based on the polycrystalline thin film which synthesized via dissolution & recrystallization in organic solvent. However, it has limitations such as irregular morphologies with randomly oriented grains, which cause large grain boundaries which deteriorate carrier lifetime and diffusion length. Despite the versatility of solution-based synthesis, however, the as-prepared perovskite films exhibit relatively irregular surface roughness implying the existence of randomly-oriented crystal domains and large density of grain boundaries, which ultimately reduce the device performance and lifetime. Moreover, the device fabrication based on the typical “top-down” lithography remains difficult to apply due to the general instability of OHIPs to the solvents involved in the process. However, it has limitations such as irregular morphologies with randomly oriented grains, which cause large grain boundaries which deteriorate carrier lifetime and diffusion length. In this study, we report the CVD patterning of lead iodide (PbI ) thin films on a micro-scale pre-patterned Si substrate by P(NBOC-r-GMA) polymer, followed by conversion into CH NH PbI using methylammonium iodide (CH NH I) vapor.