High-performance inverted perovskite solar cells using 4-diaminomethylbenzoic as a passivant.

Grain boundary (GB) and interface passivation of perovskite films impacts the efficiency and stability of perovskite solar cells (PSCs) dramatically. Here, an efficient passivation strategy using 4-diaminomethylbenzoic (4-DA) followed by thermal annealing treatment is proposed to improve the performance of PSCs. We have systemically investigated the impact of 4-DA on the physical properties of the perovskite layer and corresponding performance of the inverted PSCs. The results show that the contact between crystalline grains is improved, and high quality MAPbI films are successfully prepared, which result in the elimination of trap states and enhanced performance of the devices. The highest power conversion efficiency (PCE) of 20.58% is achieved in this work. Meanwhile, the devices show enhanced stability and the average PCE values almost remained the same after 168 hours of storage without any encapsulation. The passivation method developed in this work shows a novel strategy toward the fabrication of inverted PSCs with high efficiency and high stability.