Fast Optical Reflectance Measurements during Spin Coating and Annealing of Organic–Inorganic Perovskite Precursor Solutions

Abstract

In article number 2000479, Jörg Rappich and co-workers address early stages of film formation and crystallization of organic lead triiodide perovskites by employing in-situ high-speed spectral reflectance measurements. The time scale ranges from 0.2 milliseconds to seconds. Data were taken during spincoating and subsequent low-temperature annealing. The measurements enable the investigation of changes in the solution of the spin-coating process. The evaporation of the solvent during spin-coating results in the spontaneous crystallization of the perovskite layer. During the subsequent annealing process, the diffuse reflectance measured with high sensitivity provides insight into the transformation and crystallization process of the precursor layer to the final perovskite layer.