Exploiting localized charge accumulation regions in alloyed hybrid perovskites for highly efficient luminescence (Conference Presentation)
Exploiting localized charge accumulation regions in alloyed hybrid perovskites for highly efficient luminescence (Conference Presentation)
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利用合金杂化钙钛矿中的局部电荷积累区域实现高效发光（会议演示）
DOI：
10.1117/12.2543694
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Feldmann S
中科院分区：
文献类型：
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作者：
Feldmann S
混合钙钛矿已经成为光电应用的特殊半导体。在这里，我们通过改变混合卤化物钙钛矿中的电荷载流子动力学来控制阳离子合金化以推动光电性能。与单卤化物钙钛矿相比，我们发现光激发载流子密度远低于太阳光照条件下的高发光产率。使用时间分辨光谱，我们表明，电荷载流子复合制度的变化从第二到第一顺序内的第一个几十纳秒激发后。通过光学带隙和元素组成的微尺度映射，电选通输运测量和第一性原理计算，我们证明了电子状态中的空间变化的能量无序导致局部电荷积累，产生p型和n型光掺杂区域，这揭示了太阳能电池和LED在低电荷注入下有效发光的策略。
Hybrid perovskites have emerged as exceptional semiconductors for optoelectronic applications. Here, we control the cation alloying to push optoelectronic performance through alteration of the charge carrier dynamics in mixed-halide perovskites. In contrast to single-halide perovskites, we find high luminescence yields for photo-excited carrier densities far below solar illumination conditions. Using time-resolved spectroscopy we show that the charge-carrier recombination regime changes from second to first order within the first tens of nanoseconds after excitation. Supported by microscale-mapping of the optical bandgap and elemental composition, electrically-gated transport measurements and first-principles calculations, we demonstrate that spatially-varying energetic disorder in the electronic states causes local charge accumulation, creating p- and n-type photo-doped regions, which unearths a strategy for efficient light emission at low charge-injection in solar cells and LEDs.