Encapsulation for long-term stability enhancement of perovskite solar cells

- Large area devices (1 cm2) were realized with high reproducibility showing a maximum efficiency of 15.4%.
- Several sealing procedures were performed to minimize the effect of the sealing on the initial performance of the PSCs.
- The optimized SP helps to study the intrinsic stability of PSCs during damp-heat, dry-heat and light soaking tests.
- For the first time, we show the role of the HTL dopants in the light-soaking test at MPP to stabilize the PV performance.
- Cross-sectional STEM characterization was performed to compare the perovskite morphology of fresh and aged cells.

Perovskite Solar Cells (PSCs) have achieved power conversion efficiencies (PCEs) comparable to established technologies, but their stability in real-life working conditions - including exposure to moisture, heat and light - has still not been decisively demonstrated. Encapsulation of the cells is vital for increasing device lifetime, as well as shedding light on the intrinsic degradation process of the active layers. Here we compare different sealing protocols applied to large area cells (1 cm2, average PCE 13.6%) to separate the extrinsic degradation, due to the external environment, from the intrinsic one, due to the materials themselves. Sealing methods were tested against accelerated life-time tests - damp-heating, prolonged heating and light-soaking. We thus developed and tested a novel sealing procedure that makes PSCs able to maintain a stabilized 10% PCE after heat, light and moisture stress.

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