The real-world deployment of the organic-inorganic hybrid perovskite solar cells is hindered by their instability to external stimuli such as heat and moisture. The low-dimensional perovskite (LDP), consisting of layered perovskite slabs separated by large organic spacers, is a promising candidate to address the stability issues while maintaining the remarkable optoelectronic properties. Much effort has been devoted to the LDP film preparation and device architecture optimization. However, the fundamental knowledge about the structure, composition and degradation mechanism of the LDP materials, which are prerequisites for further advancements in device performance, is still lacking.
In a study led by Prof. Chen Gang at SPST, researchers unveiled the structural characteristics and degradation kinetics of the widely adopted butylammonium-based LDP material through a systematic investigation employing the synchrotron-based X-ray techniques. These techniques fully depict the unique crystal stacking pattern of the LDP film, which contains highly oriented perovskite crystals of different layer thicknesses. It is also revealed that the LDP film undergoes a divergent degradation process under thermal stress and a uniquely disproportionate degradation process under high-humidity condition. These insights inspired the development of an effective self-passivation strategy for the LDP films, which concurrently improves the device’s efficiency and stability. The current work provides both mechanistic insights and technical advancements towards the fabrication of highly efficient and stable LDP-based solar cells.
Prof. Chen and his research group have conducted a series of in situ studies on these organic-inorganic hybrid perovskite materials. They believe that such innovative and theoretical investigations will advance the development of the perovskite solar cell technology and inspire the broad research community.
The study was published in an article entitled “Self-Passivation of Low-Dimensional Hybrid Halide Perovskites Guided by Structural Characteristics and Degradation Kinetics” in the journal Energy & Environment Science. The first author of the paper was Dr. Meng Ke at SPST and the corresponding author was Prof. Chen Gang.
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Fig.1 Structural investigation of the low dimensional perovskite
Fig 2. Schematic illustration of the low dimensional perovskite