Efficient and bending durable flexible perovskite solar cells via interface modification using a combination of thin MoS2 nanosheets and molecules binding to the perovskite

In this work, efficient and bending durable flexible perovskite solar cells are obtained by modification of the perovskite film surface with 1- dodecanethiol (DT) followed by drop-casting of pre-dispersed thin nanosheets of MoS2. Our results show an enhancement in efficiency of the flexible device after the interface modification and revealed that the DT and MoS2 modified device recovers completely its initial values of PCE and FF, current density, and open-circuit voltage after 300 bending cycles while the standard device resembles only 50% of its PCE. Following a standard light cycling protocol for unencapsulated devices, it revealed an apparent PCE drop of the standard device up to 32% of its maximum value while the modified device recovers 95% of its highest PCE value. Different characterization methods suggest that the surface modification method induces hydrophobicity as well as significantly reduces the interface trap density.