Inducing swift nucleation morphology control for efficient planar perovskite solar cells by hot-air quenching

We introduce 1 step pin-hole free CH3NH3PbI3-xClx perovskite layers by using heated airflow during the nucleation stage of the perovskite. Upon employing heated air, we stimulate uniformly distributed nuclei growth, resulting in a pin-hole free planar perovskite layer. We find an optimized heated airflow of 100 degree C as the optimized condition. The resulting planar device employing a conventional TiO2 electron transporting layer exhibits 17.6% average power conversion efficiency with 14.3% maximum powerpoint (MPP) efficiency. In addition, our method gives a very reproducible perovskite layer. Thus, our pin-hole free perovskite layer allows for 14.9% efficiency in a larger area device (0.71 cm2) that is generally prone to shunting paths.