Improving the efficiency and stability of in-air fabricated perovskite solar cells using the mixed antisolvent of methyl acetate and chloroform
Martin Eze, Val Hyginus Udoka Eze, Godwin Ugwuanyi, Mohammad Alnajideen, Abdulhamid Atia, Samuel Chukwuemeka Olisa, Victoria G. Rocha, Gao Min
Abstract
Antisolvents play a significant role in obtaining high-quality perovskite films during the fabrication process. This paper reports a novel mixture of two antisolvents (methyl acetate and chloroform) that proves effective for fabricating high-quality perovskite films in a high humidity ambient. The results show that the use of methyl acetate alone as the antisolvent enables the fabrication of dense perovskite films (MAPbI3) in a high humidity ambient, but with a rough surface, while mixing methyl acetate with an appropriate amount of chloroform produces not only dense perovskite films but also smooth surfaces. As a result, the power conversion efficiency (PCE) is increased from 17.1% of the devices treated with methyl acetate alone to 18.6% of the devices treated with the mixed antisolvent of methyl acetate (70%) and chloroform (30%). The stability of the devices was also improved significantly for the devices treated with the mixed antisolvent of methyl acetate (85%) and chloroform (15%), which exhibit a slow degradation of 7% in PCE after 552 h of storage, compared to 22% for the devices treated with methyl acetate alone.