Rapid crystallization and controllable growth of perovskite thin films via a seeded approach

Abstract

Organic–inorganic hybrid perovskite solar cells (PVSCs) have attracted extensive attention due to high efficiency, easy fabrication, and low-cost solution processes. One of the keys to achieve high-performance cost-effective PVSCs is to attain rapid crystallization with controlled morphology of the perovskite films. Herein, the authors report a technique for the rapid crystallization of perovskite with tunable crystal grain size and morphology via a seeded approach. Specifically, a solution of lead iodide (PbI2) was spin coated on a substrate, and a low-concentration solution of methylammonium iodide (MAI) was dropped onto the PbI2 film to form perovskite seeds prior to introducing high-concentration solution of MAI. The seeded nucleation and growth lead to dense and uniform perovskite thin films with controllable crystal grains. This seeded crystallization technique offers an effective way to boost the low-cost manufacture of efficient and reproducible PVSCs.