Realizing efficient and stable hybrid perovskite solar cells via passivation with Mn2+ ion-doped CsPbCl3 inorganic metal halide perovskite quantum dots

초록

The passivation of ionic defects at the surface and grain boundaries of hybrid perovskite (PVK) thin films is crucial for realizing high power conversion efficiency (PCE) and stable perovskite solar cells (PSCs). In this study, a new method is demonstrated to passivate PVK thin films. This method proposes the controllable synthesis to increase concentration of Mn2+ ion dopants in CsPbCl3 quantum dots (QDs) using Pb(CH3CO2)2 & sdot;3H2O, Mn (C2H3O2)2 & sdot;4H2O, and N-chlorophthalimide as precursors, and the application of the synthesized CsPbCl3:Mn2+ QDs for the passivation of PVK thin films. The QDs are utilized to distribute elemental dopants, such as Cs+, Cl , and Mn2+ across (FAPbI3)0.92(MAPbBr3)0.08 thin films and to attach ligands to the surface of the thin films. The Mn2+ and Cl ions in the QDs are found to migrate into the thin films through grain boundaries. This migration enhances the vertical crystallization and reduces bulk defects in the thin films, as ligands introduced by QDs improve the band alignment of PVK thin films with a hole transport layer, consequently increasing the PCE of the PSCs from 21.3 % to 22.8 %. Also, hydrophobic ligands improve cell stability, maintaining 88 % of the initial PCE after 500 h of storage in ambient air by inhibiting moisture penetration.

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