Probing the Origin of Light-Enhanced Ion Diffusion in Halide Perovskites
Probing the Origin of Light-Enhanced Ion Diffusion in Halide Perovskites
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DOI：
10.1021/acsami.1c05268
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发表时间：
2021-07-12
影响因子：
9.5
通讯作者：
Wu, Judy Z.
中科院分区：
文献类型：
--
作者：
Marshall, Angelo D.;Acharya, Jagaran;Wu, Judy Z.
有机-无机混合卤化物钙钛矿是近年来出现的一种非常有前途的光电子材料，如光电子器件和光探测器。这些材料的一个独特特征是离子扩散，通过影响电荷传输和捕获直接影响光电过程。为了揭示离子扩散行为，在不同强度的稳态和动态可见光照射下，研究了少量掺杂苯基-C61-丁酸甲酯的混合钙钛矿MAPbI（3）和MAPbI（3）薄膜电容器。光诱导电容，这与光强度的增加单调增加，观察到在低频范围内低于300 kHz的电场上，而定量不同。特别地，在MAPbI（3）-PCBM电容器中，在黑暗中可以在MAPbI（3）-PCBM电容器中获得大的光诱导电容。另外，在PCBM诱导的电子陷阱作用下，后者的电容随光强的增加要小得多。该结果表明，MAPbI（3）电容器中的光致电容可以归因于与由照射激活的离子扩散相关的电容器两端的附加电荷的贡献，并且由于MAPbI（3）-PCBM样品中捕获的残余光激发电子，在照射关闭后对电容的影响将保持。
Organic-inorganic hybrid halide perovskites have emerged recently as highly promising materials for optoelectronics such as photovoltaics and photodetectors. A unique feature of these materials is ion diffusion that directly impacts the optoelectronic process by affecting the charge transport and trapping. In order to shed light on the ionic diffusion behavior, the hybrid perovskites MAPbI(3) and MAPbI(3) with minor doping of phenyl-C61-butyric acid methyl-ester (MAPbI(3)-PCBM) thin-film capacitors were investigated in the presence of steady and dynamic visible illumination of different intensities. Light-induced capacitance, which increases monotonically with the increase of light intensity, was observed in the low-frequency range below 300 kHz of the electric field on both while differing quantitatively. Specifically, the large light-induced capacitance in the MAPbI3 capacitors can be obtained in the MAPbI(3)-PCBM ones in the dark. In addition, the increase of capacitance with light intensity is much less in the latter with electron trapping induced by PCBM. This result has revealed that the light-induced capacitance in MAPbI(3) capacitors can be ascribed to the contribution of the additional charges across the capacitors associated with ionic diffusion activated by the illumination and that the effects on the capacitance will remain after the illumination is turned off due to residual photoexcited electrons trapped in the MAPbI(3)-PCBM sample.