Reduced Self-Doping of Perovskites Induced by Short Annealing for Efficient Solar Modules

Abstract

Summary Controlling of doping in semiconducting light absorber can minimize the charge recombination and maximizing power output from solar cells; however, it is challenging for perovskites due to lack of controlled doping. Here, we report that a short post-annealing of less than 3 min for facilitating high-throughput manufacturing of perovskite solar modules in an ambient environment maintains the stoichiometric composition of perovskites, encouraging a spontaneous de-doping of perovskites during aging. The reduced self-doping results in less charge recombination and, thus, higher device efficiency. The stabilized open-circuit voltage of sub-cells in the CH3NH3PbI3 minimodules with an area >20 cm2 reaches 1.19 V on average. The aperture efficiency reaches 17.8% under one sun and 18.7% under a quarter sun illumination, deriving an averaged efficiency >20.0% for each sub-cell with an area >3 cm2, demonstrating the excellent uniformity of the films by this scalable process. The minimodule also works as uniform light-emitting devices.