Light Illumination Induced Photoluminescence Enhancement and Quenching in Lead Halide Perovskite
Light Illumination Induced Photoluminescence Enhancement and Quenching in Lead Halide Perovskite
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DOI：
10.1002/solr.201600001
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发表时间：
2017-01-01
期刊：
影响因子：
7.9
通讯作者：
Ho-Baillie, Anita
中科院分区：
文献类型：
--
作者：
Chen, Sheng;Wen, Xiaoming;Ho-Baillie, Anita
研究发现，光照(浸泡)可以显著改变钙钛矿型太阳能电池的光电性能和性能。在这里，我们利用稳态和时间分辨光致发光(PL)技术，系统地研究了光照对包覆良好的CH3NH3PbI3钙钛矿结构的影响。在低强度连续恒定光照下，发光表现为增强或恒定；这取决于钙钛矿中缺陷态的脱陷速率和密度，而这又由制备方法决定。缺陷的固化归因于发光增强的起源。在连续较高强度的光照下，观察到与样品制备相关的不同阈值的发光猝灭。这归因于可移动离子的积累导致电子/空穴非辐射复合的增加。我们证实了在连续光照(光浸泡)下发光的增强和猝灭部分源于钙钛矿相的本征贡献，与缺陷密度密切相关，从而与制备工艺密切相关。这些发现为理解与缺陷捕获和可移动离子相关的载流子动力学提供了新的视角，有助于理解钙钛矿太阳能电池的不稳定性。
It has been found that light illumination (soaking) can significantly change the optical and electronic properties of perovskites and the performance of perovskite solar cells. Here using steady state and time-resolved photoluminescence (PL) techniques, we investigate systematically the effect of light illumination on a well encapsulated CH3NH3PbI3 perovskites. Under a continuous constant illumination at low intensity, the PL exhibits either enhancement or constant; dependent on the detrapping rate and density of the defect states in the perovskite which in turn is determined by fabrication methods. Defect curing is attributed to the origin of the PL enhancement. Under a continuous higher intensity illumination, PL quenching is observed with different thresholds relevant to the sample fabrication. This is ascribed to mobile ion accumulation resulting in increased electron/hole non-radiative recombination. We confirmed the PL enhancement and quenching under continuous illumination (light soaking) partly originate from the intrinsic contribution of the perovskite, closely correlated to the defect density therefore the fabrication. These findings provide novel insight into the carrier dynamics correlated to the defect trapping and mobile ions which helps to understand the instability of perovskite solar cells.