3-(Aminomethyl)piperidinium Spacer-Induced Dion-Jacobson 2D Perovskite Beneath CsPbI3 for Stable and Efficient Inorganic Perovskite Solar Cells

초록

For the inorganic perovskite CsPbI3, while many strategies have focused on passivating the top surface, engineering the interface beneath the perovskite layer remains a critical yet underexplored avenue, primarily due to the high crystallization temperature and the dissolution of underlying layers during solution processing. Here, these longstanding challenges are addressed by introducing a strategic placement of a Dion-Jacobson quasi-2D perovskite layer beneath CsPbI3. Specifically, 3-(aminomethyl)piperidinium iodide (3AMPI2), an organic salt insoluble in the CsPbI3 precursor solution, is employed to form a robust quasi-2D interlayer without degradation during perovskite deposition and annealing. This bottom-layer integration passivates interfacial defects, promotes favorable crystallization of CsPbI3, and results in significantly enhanced device performance, achieving a power conversion efficiency of 20.98%, an open-circuit voltage (Voc) of 1.21 V, a short-circuit current density (Jsc) of 20.59 mAcm-2, and a fill factor of 84.21%, along with robust long-term operational stability. The findings demonstrate a targeted interfacial design approach that unlocks new opportunities for simultaneously optimizing efficiency and stability in inorganic perovskite photovoltaics.

키워드