Shape-controlled CH₃NH₃PbI₃ nanoparticles for planar heterojunction perovskite solar cells

Abstract

Abstract Hybrid organic/inorganic perovskites such as methylammonium lead iodide (CH 3 NH 3 PbI 3 ) are potential candidates for thin-film photovoltaics because of their excellent cost- and energy-efficient light absorption. In this work, we have prepared CH 3 NH 3 PbI 3 nanoparticles (NPs) on the TiO x /ITO glass substrates by a simple spin-coating method to control the size and shape of NPs. The effect of varying the weight percentage (wt %) of ionic liquid (IL) has also been investigated. Analysis of the films revealed spherical NP morphology in the presence of 1, 3, and 7 wt % IL with respective diameters of 540, 350, and 600 nm. Conversely, 10 wt % IL resulted in irregular aggregation of NP blocks. The power conversion efficiency (PCE) changed upon varying the NP size, shape, and morphology. The optimization of the concentration with 3 wt % IL yielded NPs with the most uniform shape, size, and morphology and, consequently, the maximum PCE.