Study on the prevention of moisture intrusion of different shielding gas environments for stable perovskite solar cells.

• Exploring the inhibition of moisture intrusion and the protection of perovskite solar cells in a CO 2 and N 2 sealed environment. • Established the model of moisture intrusion under the environment of N 2 , CO 2 and SF 6 , and simulated the degree of moisture intrusion under the three gas environments. • In the practical application of perovskite solar cells, on the premise of considering sealing and cost, it provides guidance for the selection of shielding gas. The stability and reliability of perovskite solar cells (PSCs) are severely affected by moisture. Therefore, it is very meaningful to study the barrier effect of gases with different compositions on moisture in a sealed environment. In this work, the stability of PSCs in a sealed environment filled with N 2 , CO 2 with an external environment of 45 °C and 85% RH was investigated. After 240 h treatment, the PCE of the PSCs in the CO 2 sealed environment decayed to 71.1% of the initial value. The PCE of the PSCs in the N 2 sealed environment decayed to 51.8% of the initial value, while in the air environment as a control, the PCE decayed to 36.3% of the initial value. Through SEM, XRD film characterization and finite element simulation, it is found that both CO 2 and N 2 can be used as shielding gases to inhibit moisture intrusion, thereby slowing down the decay rate of perovskite solar cells. And CO 2 is more effective than N 2 in inhibiting moisture intrusion. On the one hand, CO 2 molecules are larger than N 2 molecules. When tiny gaps appear in the sealed environment, N 2 molecules can escape, but CO 2 cannot escape, which will lead to less moisture intrusion in the CO 2 sealed environment. On the other hand, when there are large gaps in the sealed environment, both N 2 and CO 2 can escape, because the diffusion coefficient of moisture in the N 2 sealed environment is larger, resulting in more moisture intrusion in the N 2 sealed environment. [ABSTRACT FROM AUTHOR]