Covering effect of conductive glass: a facile route to tailor the grain growth of hybrid perovskites for highly efficient solar cells

Abstract

Effective control of the perovskite crystallinity, homogeneity and surface morphology is very important for state-of-the-art perovskite solar cells to retard the charge recombination at the grain boundaries. In this work, we develop a facile approach to promote the growth of high quality perovskite films that features a conductive glass-assisted annealing route. Such a novel annealing route not only confines the evaporation of the residual solvent effectively to gain high-crystallinity and micrometer-sized grains of CH₃NH₃PbI₃ films, but also decreases the number of non-radiative recombination sites and facilitates charge transportation in the microstructural perovskite films dramatically compared with those obtained through the conventional annealing route, resulting in a remarkably improved power conversion efficiency along with an inconspicuous hysteresis. The best performing cell exhibits a PCE boosted to 18.08% compared with 16.18% achieved in the control one. And the optimized 1 cm² device based on the reported method shows a satisfactory efficiency of 15.77%.