Excitation Density Dependent Photoluminescence Quenching and Charge Transfer Efficiencies in Hybrid Perovskite/Organic Semiconductor Bilayers
Excitation Density Dependent Photoluminescence Quenching and Charge Transfer Efficiencies in Hybrid Perovskite/Organic Semiconductor Bilayers
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DOI：
10.1002/aenm.201802474
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发表时间：
2018-12-01
影响因子：
27.8
通讯作者：
Durrant, James R.
中科院分区：
文献类型：
--
作者：
Kim, Jinhyun;Godin, Robert;Durrant, James R.
本文研究了甲基碘化铅铵（PbI（3））与PC61 BM或聚（3，4-乙撑二氧噻吩）：聚苯乙烯磺酸盐（PEDOT：PSS）电荷转移层之间的电荷转移效率对激发强度的依赖性。它通过采用一系列光学测量，包括稳态（SS）光致发光猝灭（PLQ）和瞬态光致发光和吸收在很宽的激发密度范围内，分析界面电子/空穴转移和电荷捕获和复合之间的动力学竞争（3）。结果表明，PLQ测量与一个典型的光致发光光谱仪可以产生显着不同的转移效率下测量1太阳照射。稳态和脉冲测量表明，由于快速双分子复合，在低激发条件下（5E + 17 cm（-3））的低转移效率。有效转移到PC61 BM或PEDOT：PSS仅在中间激发条件下观察到（近似1个太阳照射），其中电子和空穴转移时间分别确定为36和11 ns。结果进行了讨论，在其相关性的激发密度的依赖性的设备光电流的产生，电荷捕获对这种依赖性的影响，和适当的方法来确定电荷转移效率相关的设备性能。
This study addresses the dependence of charge transfer efficiency between bilayers of methylammonium lead iodide (MAPI(3)) with PC61BM or poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) charge transfer layers on excitation intensity. It analyzes the kinetic competition between interfacial electron/hole transfer and charge trapping and recombination within MAPI(3) by employing a range of optical measurements including steady-state (SS) photoluminescence quenching (PLQ), and transient photoluminescence and absorption over a broad range of excitation densities. The results indicate that PLQ measurements with a typical photoluminescence spectrometer can yield significantly different transfer efficiencies to those measured under 1 Sun irradiation. Steady-state and pulsed measurements indicate low transfer efficiencies at low excitation conditions (5E + 17 cm(-3)) due to fast bimolecular recombination. Efficient transfer to PC61BM or PEDOT:PSS is only observed under intermediate excitation conditions (approximate to 1 Sun irradiation) where electron and hole transfer times are determined to be 36 and 11 ns, respectively. The results are discussed in terms of their relevance to the excitation density dependence of device photocurrent generation, impact of charge trapping on this dependence, and appropriate methodologies to determine charge transfer efficiencies relevant to device performance.