A metal-organic hybrid perovskite (CH₃NH₃PbI₃) with three-dimensional framework of metal-halide octahedra has been reported as a low-cost, solution-processable absorber for a thin-film solar cell with a power-conversion efficiency over 20%. Low-dimensional layered perovskites with metal halide slabs separated by the insulating organic layers are reported to show higher stability, but the efficiencies of the solar cells are limited by the confinement of excitons. In order to explore the confinement and transport of excitons in zero-dimensional metal-organic hybrid materials, a highly orientated film of (CH₃NH₃)₃Bi₂I₉ with nanometre-sized core clusters of Bi₂I₉^3- surrounded by insulating CH₃NH₃⁺ was prepared via solution processing. The (CH₃NH₃)₃Bi₂I₉ film shows highly anisotropic photoluminescence emission and excitation due to the large proportion of localised excitons coupled with delocalised excitons from intercluster energy transfer. The abrupt increase in photoluminescence quantum yield at excitation energy above twice band gap could indicate a quantum cutting due to the low dimensionality.Understanding the confinement and transport of excitons in low dimensional systems will aid the development of next generation photovoltaics. Via photophysical studies Ni et al. observe 'quantum cutting' in 0D metal-organic hybrid materials based on methylammonium bismuth halide (CH₃NH₃)3Bi₂I₉.

中文翻译：

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电荷载体位于零维（CH3NH3）3Bi2I9簇中。

据报道，具有金属卤化物八面体三维框架的金属有机杂化钙钛矿（CH ₃ NH ₃ PbI ₃）是一种低成本，可溶液加工的薄膜太阳能电池吸收器，具有功率转换效率超过20％。据报道，低维层状钙钛矿具有被绝缘有机层隔开的金属卤化物平板，显示出更高的稳定性，但是太阳能电池的效率受到激子的限制。为了探索激子在零维金属-有机杂化材料中的限制和传输，研究了（CH ₃ NH ₃）₃ Bi ₂ I ₉的高取向膜通过溶液处理制备了具有纳米级Bi ₂ I ₉ ^3-的核簇，被绝缘的CH ₃ NH ₃ ⁺包围。（CH ₃ NH ₃）₃ Bi ₂ I ₉薄膜显示出高度各向异性的光致发光发射和激发，这是由于大量的局部激子与来自簇间能量转移的离域激子所致。激发能在两倍的带隙以上时，光致发光量子产率的突然增加可能表明由于尺寸低而导致了量子切割。了解激子在低维系统中的约束和输运将有助于下一代光伏的发展。通过光物理研究Ni等。观察基于甲基卤化铋铵（CH ₃ NH ₃）3Bi ₂ I _9的0D金属-有机杂化材料的“量子切割” 。