Suppressed phase separation of mixed-halide perovskites confined in endotaxial matrices
Suppressed phase separation of mixed-halide perovskites confined in endotaxial matrices
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DOI：
10.1038/s41467-019-08610-6
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发表时间：
2019-02
影响因子：
16.6
通讯作者：
Xi Wang;Yichuan Ling;X. Lian;Y. Xin;Kamal B. Dhungana;Fernando Perez-Orive;Javon M. Knox;
中科院分区：
文献类型：
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作者：
Xi Wang;Yichuan Ling;X. Lian;Y. Xin;Kamal B. Dhungana;Fernando Perez-Orive;Javon M. Knox;
半导体的功能和性能由其带隙决定。例如在InxGa 1-xN中，合金化已经是用于调整带隙的主流策略。然而，将半导体合金保持在混溶间隙中（均匀）并不是微不足道的。这一挑战现在正在扩展到卤化物钙钛矿-一种新兴的光伏材料。虽然可以通过混合不同的卤素离子来方便地调节带隙，如在CsPb（BrxI 1-x）3中，但所谓的混合卤化物钙钛矿在光照下遭受严重的相分离。在这里，我们发现，这种相分离可以高度抑制嵌入纳米晶体的混合卤化物钙钛矿的内轴矩阵。调谐的带隙在极强的光照下保持非常稳定。实验和成核模型之间的协议表明，纳米晶体的大小和主客体界面的光稳定性是至关重要的。稳定的带隙对于钙钛矿基光电子学的发展至关重要，例如串联太阳能电池和全色LED。
The functionality and performance of a semiconductor is determined by its bandgap. Alloying, as for instance in InxGa1-xN, has been a mainstream strategy for tuning the bandgap. Keeping the semiconductor alloys in the miscibility gap (being homogeneous), however, is non-trivial. This challenge is now being extended to halide perovskites – an emerging class of photovoltaic materials. While the bandgap can be conveniently tuned by mixing different halogen ions, as in CsPb(BrxI1-x)3, the so-called mixed-halide perovskites suffer from severe phase separation under illumination. Here, we discover that such phase separation can be highly suppressed by embedding nanocrystals of mixed-halide perovskites in an endotaxial matrix. The tuned bandgap remains remarkably stable under extremely intensive illumination. The agreement between the experiments and a nucleation model suggests that the size of the nanocrystals and the host-guest interfaces are critical for the photo-stability. The stabilized bandgap will be essential for the development of perovskite-based optoelectronics, such as tandem solar cells and full-color LEDs.