Figure 5.

(a) Operation mechanism of quasi-2D perovskite photovoltaics and the correlation between the band structure, energy disorder, and V_oc of the device. Reprinted with permission from ref (80). Copyright 2020 Springer Nature. (b) QFLS is calculated from the PLQY for the neat material and the full device (left), and different types of energy losses are calculated from the left to compare the contribution of the other recombination processes for each system (right). Reprinted with permission from ref (93). Copyright 2019 Wiley VCH. (c) An open-circuit voltage loss can be caused by either increased recombination that lowers the charge carrier density (left) or broadening of the density of states with unchanged charge carrier density (right). Reprinted with permission from ref (89). Copyright 2015 Wiley-VCH. (d) QFLS and V_oc losses are in the bulk and at the interfaces and electrodes. The QFLS obtained in the bulk of the layered perovskites and MAPI (blue hexagons) is impacted by radiative (red shaded area) and nonradiative (light blue shaded area) recombination losses, while the QFLS in the p-i-n stacks (green diamonds) is affected by additional nonradiative interfacial recombination losses (blue shaded area). The presence of the electrodes in the final cell causes additional nonradiative recombination losses concerning the QFLS of the p-i-n stack (turquoise shaded area). Reprinted with permission from ref (94). Copyright 2021 Elsevier. (e) Illustration of the ion migration pathways enabled by lattice distortions due to accumulated charges, dissolved impurities, and nonuniform strain caused by the piezoelectric effect. Reprinted with permission from ref (95). Copyright 2016 American Chemical Society.