Enhanced Moisture Stability of Perovskite Solar Cells With Mixed-Dimensional and Mixed-Compositional Light-Absorbing Materials

In spite of perovskite solar cells have achieved great progress in recent years, the long term stability of perovskite material is always a big obstacle before commercialization, especially the moisture instability. In this paper, we reported a layered perovskite solar cell based on (CF3CH2NH2)(2)(FA(0.825)MA(0.15)Cs(0.025))(n-1)Pb-n(I0.85Br0.15)(3n+1) series (n=1-infinity), which possess excellent optoelectronic property and stability. The perovskite film displayed an ultrahigh surface coverage and provided high-quality thin films which lead to an advancement in solar cells performance. We had fabricated solar cells based on (CF3CH2NH2)(2)(FA(0.825)MA(0.15)Cs(0.025))(29)Pb-30(I0.85Br0.15)(91) light absorber and got the best PCE of 18.17%. The average PCE of 17.84% was achieved with J(sc) of 21.05mAcm(-2), V-oc of 1.095V, and FF of 77.4%. Moreover, the multi-layered perovskite showed excellent property of moisture-resistant compared to three-dimensional type PSCs. Under relative humidity level of 65%, the devices without any encapsulation did not deteriorate for up to approximately 28 days with the PCE maintaining over 90%.