Li Xuemei, Huang Wengang, Krajnc Andraž, Yang Yuwei, Shukla Atul, Lee Jaeho, Ghasemi Mehri, Martens Isaac, Chan Bun, Appadoo Dominique, Chen Peng, Wen Xiaoming, Steele Julian A, Hackbarth Haira G, Sun Qiang, Mali Gregor, Lin Rijia, Bedford Nicholas M, Chen Vicki, Cheetham Anthony K, Tizei Luiz H G, Collins Sean M, Wang Lianzhou, Hou Jingwei
School of Chemical Engineering, The University of Queensland, St Lucia, QLD, 4072, Australia.
Department of Inorganic Chemistry and Technology, National Institute of Chemistry, 1001, Ljubljana, Slovenia.
Nat Commun. 2023 Nov 22;14(1):7612. doi: 10.1038/s41467-023-43247-6.
The stellar optoelectronic properties of metal halide perovskites provide enormous promise for next-generation optical devices with excellent conversion efficiencies and lower manufacturing costs. However, there is a long-standing ambiguity as to whether the perovskite surface/interface (e.g. structure, charge transfer or source of off-target recombination) or bulk properties are the more determining factor in device performance. Here we fabricate an array of CsPbI crystal and hybrid glass composites by sintering and globally visualise the property-performance landscape. Our findings reveal that the interface is the primary determinant of the crystal phases, optoelectronic quality, and stability of CsPbI. In particular, the presence of a diffusion "alloying" layer is discovered to be critical for passivating surface traps, and beneficially altering the energy landscape of crystal phases. However, high-temperature sintering results in the promotion of a non-stoichiometric perovskite and excess traps at the interface, despite the short-range structure of halide is retained within the alloying layer. By shedding light on functional hetero-interfaces, our research offers the key factors for engineering high-performance perovskite devices.
金属卤化物钙钛矿的优异光电特性为下一代具有卓越转换效率和更低制造成本的光学器件带来了巨大希望。然而，长期以来一直存在一个疑问，即钙钛矿的表面/界面（例如结构、电荷转移或非目标复合的来源）还是体相性质在器件性能中起更决定性的作用。在此，我们通过烧结制备了一系列CsPbI晶体与混合玻璃复合材料阵列，并全面直观地呈现了性能-特性全貌。我们的研究结果表明，界面是CsPbI晶体相、光电质量和稳定性的主要决定因素。特别地，发现扩散“合金化”层的存在对于钝化表面陷阱以及有益地改变晶体相的能量分布至关重要。然而，尽管卤化物的短程结构在合金化层中得以保留，但高温烧结会促进非化学计量比钙钛矿的形成以及界面处过量陷阱的产生。通过揭示功能性异质界面，我们的研究为设计高性能钙钛矿器件提供了关键因素。
