Efficient Perovskite Solar Cells by Temperature Control in Single and Mixed Halide Precursor Solutions and Films

Abstract

Thermal annealing and precursor composition play critical roles in crystallinity control and morphology formation of perovskite thin films for achieving higher photovoltaic performance. In this study we have systematically studied the role of annealing temperature on the crystallinity of perovskite (CHNH3PbI3) thin films cast from single (without PbCl2) and mixed (with PbCl2) halide precursors. Higher annealing temperature leads to agglomeration of perovskite crystals. The effects of annealing temperature on the performance of perovskite solar cells are different in single and mixed halide processed films. It is observed that the perovskite crystallinity and film formation can be altered with the addition of lead chloride in the precursor solution. We report that single halide perovskite solar cells show no change in morphology and crystal size with increase in annealing temperature, which was confirmed by UV–vis absorption spectroscopy, X-ray diffraction (XRD), and atomic force microscopy (AFM). However,...