Inducing Charge Separation in Solid-State Two-Dimensional Hybrid Perovskites through the Incorporation of Organic Charge-Transfer Complexes
Inducing Charge Separation in Solid-State Two-Dimensional Hybrid Perovskites through the Incorporation of Organic Charge-Transfer Complexes
复制标题
通过引入有机电荷转移络合物诱导固体二维杂化钙钛矿中的电荷分离
DOI：
10.1021/acs.jpclett.9b03746
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发表时间：
2020-02-06
影响因子：
5.7
通讯作者：
Grozema, Ferdinand C.
中科院分区：
文献类型：
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作者：
Gelvez-Rueda, Maria C.;Van Gompel, Wouter T. M.;Grozema, Ferdinand C.
二维（2D）杂化钙钛矿构成了一类新兴的用于光电应用的材料，其中无机八面体层被非导电的大有机阳离子隔开。这导致高维和介电约束，因此高激子结合能，这严重限制了它们在需要电荷载流子分离的器件中的应用。在这项工作中，我们实现了改进的电荷分离取代非导电的有机阳离子与有机电荷转移复合物组成的芘供体和tetracyanoquinodimethane受体。稳态吸收测量表明，这些材料表现出的光学特性，与有机电荷转移复合物的吸收相匹配。使用微波电导率和飞秒瞬态吸收，我们表明，这些电荷转移状态的光激发导致长寿命的移动的电荷在无机层。虽然电荷分离的效率相对较低，但这些实验表明，通过设计有机层可以在固态2D钙钛矿中诱导电荷分离。
Two-dimensional (2D) hybrid perovskites make up an emerging class of materials for optoelectronic applications in which inorganic octahedral layers are separated by nonconductive large organic cations. This leads to a high-dimensional and dielectric confinement and hence a high exciton binding energy, which severely limits their application in devices in which charge carrier separation is required. In this work, we achieve improved charge separation by replacing nonconductive organic cations with organic charge-transfer complexes consisting of a pyrene donor and a tetracyanoquinodimethane acceptor. Steady-state absorption measurements show that these materials exhibit optical features that match with the absorption of the organic charge-transfer complexes. Using microwave conductivity and femtosecond transient absorption, we show that photoexcitation of these charge-transfer states leads to long-lived mobile charges in the inorganic layers. While the efficiency of charge separation is relatively low, these experiments demonstrate that it is possible to induce charge separation in solid-state 2D perovskites by engineering the organic layer.