Encounter-Limited Charge-Carrier Recombination in Phase-Separated Organic Semiconductor Blends
Encounter-Limited Charge-Carrier Recombination in Phase-Separated Organic Semiconductor Blends
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DOI：
10.1103/physrevlett.114.136602
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发表时间：
2015-04-01
影响因子：
8.6
通讯作者：
Deibel, Carsten
中科院分区：
文献类型：
--
作者：
Heiber, Michael C.;Baumbach, Christoph;Deibel, Carsten
采用动力学Monte Carlo模拟方法研究了有机半导体共混物中相分离对载流子限幅复合的影响。使用模型体异质结的形态，对域的大小和载流子迁移率的复合率的依赖进行量化。统一的竞争模型和模拟结果，我们表明，迁移率的复合率的依赖性，可以描述使用的功率平均值的电子和空穴迁移率与域大小相关的指数。此外，对于典型的有机光伏器件的域尺寸，我们发现相分离降低复合率小于一个数量级相比，朗之万模型和迁移率的依赖性可以近似的几何平均值。
The theoretical effects of phase separation on encounter-limited charge carrier recombination in organic semiconductor blends are investigated using kinetic Monte Carlo simulations of pump-probe experiments. Using model bulk heterojunction morphologies, the dependence of the recombination rate on domain size and charge carrier mobility are quantified. Unifying competing models and simulation results, we show that the mobility dependence of the recombination rate can be described using the power mean of the electron and hole mobilities with a domain-size-dependent exponent. Additionally, for domain sizes typical of organic photovoltaic devices, we find that phase separation reduces the recombination rate by less than one order of magnitude compared to the Langevin model and that the mobility dependence can be approximated by the geometric mean.