Boosting optoelectronic performance of MAPbI3 perovskite solar cells via ethylammonium chloride additive engineering

Abstract

The quality of the perovskite light absorption layer plays a dynamic role in the photovoltaic properties of solar cells. The existing methods to prepare methylammonium lead iodide (MAPbI3) films render substantial structural defect density, particularly at the grain boundaries and film surface, constituting a challenge that hinders the further optoelectronic enhancement of perovskite solar cells. Herein, a unique approach was introduced: using a simple ethylammonium chloride (EACl) additive in perovskite precursor mixture to produce high-quality MAPbI3 thin films. The results indicated that EACl could encourage perovskite crystal growth without experiencing the intermediate phase formation and would evaporate from the perovskite after annealing. Additionally, a gradient perovskite structure was achieved using this technique, which impressively enhanced the performance of the perovskite films. A high power conversion efficiency (PCE) of 20.03% was achieved under the optimal amount of EACl, and the resultant efficient device could retain over 89% of the original PCE after aging for 1000 h at room temperature. This novel technique leads to a facile fabrication of high-quality and less-defect perovskite thin films for competent and stable devices.