ENGINEERING NANOSTRUCTURED PEROVSKITE INTERFACES TO BOOST SOLAR CELL EFFICIENCY AND DURABILITY

Abstract

High-efficiency PSCs benefit from cheap fabrication processes, yet suffer from insufficient performance in terms of interfacial recombination and poor stability. In our research, we present an effective nanoscale interface engineering strategy for improving both charge extraction efficiency and stability in PSCs. Specifically, we utilize a passivation layer based on quasi-2D perovskites and metal oxide nanoparticles (TiO₂). Such nanostructure provides beneficial effects such as the increase of crystallization degree and defects reduction, supported by the appearance of sharper diffraction lines and significant photoluminescence quenching. As a result, we obtain devices with 22.4% efficiency as opposed to 17.8% efficiency obtained for control samples, as well as a higher fill factor and open circuit voltage. Moreover, our modified devices preserve their properties at a stable level during 1000 hours of light exposure, showing no more than 10% decrease in efficiency, while control devices lose their initial efficiency down to 50%. The developed approach also improves thermal (up to 85 °C) and humid (65% relative humidity) stability. Mechanistically, the enhanced properties can be attributed to efficient trap passivation, favorable band alignment through quasi-2D/3D heterojunction, and ion migration suppression