Science News：2021 Nano Energy How to achieve 20.1% high PCE and high stability PSC through 2D-3D heterostructure?

　　Nano Energy (IF 17.881) published a study in October 2021. It is mentioned in the article that although the mesoscopic perovskite solar cell (PSC) has high efficiency, its stability is relatively poor due to the irreversible decomposition of perovskite in moisture. This paper proposes a localized Dion-Jacobson (DJ) 2D-3D heterostructure (L2D-3DH). This structure forms DJ 2D perovskite on the local surface of the 3D perovskite, so it will not be completely covered. Due to the partial coverage of DJ 2D, this structure will not hinder the charge transfer between the perovskite and the hole transport layer, and it also effectively improves the moisture stability. It has also been found that the control of crystal orientation is not critical for effective charge transfer.

　　In experiments with instruments such as solar simulators, the research results show that L2D-3DH produces a power conversion efficiency of 20.1%, which is higher than that obtained from pure 3D perovskite or conventional 2D-3D composite. Under 70% RH high humidity, 86% of the initial efficiency is maintained after 1300 hours. The author inferred that the passivation of 3D perovskite with DJ 2D plates can reduce the trap density, suppress non-radiative recombination, and enhance quasi-Fermi level splitting, so PCE can be improved.

　　The conclusion is that this study provides a simple and effective method to improve the efficiency and stability of PSC by incorporating DJ 2D in 3D perovskite.