Addressing the efficiency loss and degradation of triple cation perovskite solar cells via integrated light managing encapsulation

Here, we present a holistic encapsulation method for perovskite solar cells to address both optical performance losses at the air-cell interface as well as intrinsic and extrinsic stability challenges. Our one-step method provides shielding to PSCs from oxygen and moisture-induced degradation as well as in situ patterning for light management. As a result of embedding the antireflective coating onto the front side of the cell, the power conversion efficiency (PCE) of the PSCs was increased from 14.1 ± 0.8 % to 15.6 ± 0.8 %, indicating an 8 % relative improvement. Moreover, the encapsulated devices kept their initial performance after 90 % relative humidity and water immersion tests. The outdoor exposure test showed no degradation for the encapsulated cells after 24 h of resting at −17 °C and maximum wind speeds of 7 m/s on average. Additionally, the encapsulation strategy was instrumental in mitigating oxygen and humidity-induced degradation during ISOS-LC tests, retaining up to 80 % of the initial performance for the encapsulated devices after 360 h. This research establishes in situ encapsulation and patterning as a promising solution for reducing optical losses and extrinsic instabilities in PSCs. The choice of flexible encapsulant enables it to be used for both rigid and flexible PSCs in a wide range of applications.