Delocalized molecule surface electronic modification for enhanced performance and high environmental stability of CsPbI2Br perovskite solar cells. (December 2019)

• Record Type: Journal Article
• Authors: Wang, Zhen; Baranwal, Ajay K.; Akmal kamarudin, Muhammad; Zhang, Putao; Kapil, Gaurav; Ma, Tingli; Hayase, Shuzi
• Is Part Of: Nano energy. Volume 66(2019)
• Publication Date: 2019-12
• Subjects: Delocalized molecules -- Surface passivation -- All-inorganic perovskite -- Rapid charge transfer -- Higher performance; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2019.104180
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: All-inorganic perovskites have drawn tremendous attentions in view of their superb thermal stability. However, unavoidable defects near the perovskite surface seriously hampers carrier transport and easily results in ion accumulation at the interface of perovskite layer and charge transport layer. Herein, delocalized thiazole and imidazole derivatives iodide salts functionalized on perovskite surface have been investigated comprehensively. These two salts post-treatment on perovskite could efficiently passivate traps arising from Cs + or I − vacancies. Additionally, these highly п-conjugated delocalized molecules can contribute to the efficient charge transport and prevent ions accumulation at the interface. As a result, sulfur-contained aminothiazolium iodide (ATI) post-treated CsPbI2 Br devices showed simultaneous enhanced current density and voltage due to its higher interaction with perovskite lattice, this led to a champion efficiency of 13.91% with superb fill factor of more than 80%, which exhibited dramatic enhancement compared with the control samples (10.12%). Furthermore, surface passivation with delocalized molecules could effectively stabilize CsPbI2 Br phase at room temperature or 80 °C annealing in ambient condition (65% RH). Equally important, this surface passivation allowed competitive efficiency of 11.26% with a large-area device (1.00 cm 2 ). This high kill tolerant approach provide a new route to fabricate inorganic perovskite devices with higher efficiency and stability. Graphical abstract: Delocalized molecule surface modification on CsPbI 2 Br film surface . Delocalized organic agents with ammonium functionalities (-NH 3+ ) were post-treated on CsPbI2 Br film for surface passivation, which resulted in larger grains with reduced trap densities. Delocalized п-electrons in molecules also contributed to the more rapid carrier transfer at the interface. As s result, a much-enchaned efficiency of 13.91% with superb fill factor of 80.81% upon thiazole iodide salts treatment was achieved. Stability of perovskite devices with encapsulation under room temperature and 80°C annealing was enhanced significantly. Furthermore, competitive performance of CsPbI2 Br perovskite devices with large active area was achieved. Image 1 Highlights: Delocalized thiazole and imidazole iodide were post-treated on perovskite for surface passivation. A champion efficiency of 13.91% with superb FF of 80.81% was obtained. Tremendous stability improvement was achieved at room temperature and 80 °C annealing.