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

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 cm(2) device based on the reported method shows a satisfactory efficiency of 15.77%.