• Sutanto, A.A.; Caprioglio, P.; Drigo, N.; Hofstetter, Y.J.; Garcia-Benito, I.; Queloz, V.I.E.; Neher, D.; Nazeeruddin, M.K.; Stolterfoht, M.; Vaynzof, Y.; Grancini, G.: 2D/3D perovskite engineering eliminates interfacial recombination losses in hybrid perovskite solar cells. Chem 7 (2021), p. 1903-1916

10.1016/j.chempr.2021.04.002
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Abstract:
Interface engineering and design is paramount in the optimization of a multilayer device stack. This stands true for multi-dimensional (2D/3D) perovskite-based solar cells, in which high efficiency can be combined with promising device durability. However, the complex function of the 2D/3D device interfaces remains vague. Here, we provide the exact knowledge on the interface energetics and demonstrate that the 2D/3D perovskite interface forms a p-n junction that is capable of reducing the electron density at the hole transport layer interface and ultimately suppresses interfacial recombination. As a consequence, we demonstrate photovoltaic devices with an enhanced fill factor (FF) and open-circuit voltage (V-OC) of 1.19 V, which approaches the potential internal quasi-Fermi level splitting (QFLS) voltage of the perovskite absorber, nullifying the interfacial losses. We thus identify the essential parameters and energetic alignment scenario required for 2D/3D perovskite systems to surpass the current limitations of hybrid perovskite solar cell performances.