Modeling Spontaneous Charge Transfer at Metal/Organic Hybrid Heterostructures
Modeling Spontaneous Charge Transfer at Metal/Organic Hybrid Heterostructures
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DOI：
10.1021/acs.jpcc.9b10055
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发表时间：
2019-08
期刊：
影响因子：
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通讯作者：
V. O. Özçelik;Yingmin Li;Wei Xiong;F. Paesani
中科院分区：
文献类型：
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作者：
V. O. Özçelik;Yingmin Li;Wei Xiong;F. Paesani
杂化材料在异质结构的整体效率与界面处的电荷转移水平密切相关的光致发光中至关重要。在这里，使用各种金属/聚（3-己基噻吩）（P3 HT）异质结构模型，我们揭示了在这些接口的自发电荷转移和电子耦合的水平取决于沉积在金属衬底上的有机聚合物的构象规律。使用基于密度泛函理论（DFT）和外差振动和频产生（HD-VSFG）测量的从头算量子化学计算，我们表明，诱导区域随机性到有机聚合物修改的界面电子态的强度，杂化水平，界面电荷转移的密度和材料的电子波函数。我们提出的HD-VSFG响应的金属/P3 HT异质结包含区域规则和区域随机P3 HT结构，并表明非共振信号的量是密切相关的自发电荷转移在界面处的水平。因此，通过测量金属/P3 HT异质结的非共振响应，可以确定界面处的自发电荷转移水平。
Hybrid materials are crucial in photovoltaics where the overall efficiency of the heterostructure is closely related to the level of charge transfer at the interface. Here, using various metal / poly(3-hexylthiophene)(P3HT) heterostructure models, we reveal that the level of spontaneous charge transfer and electronic coupling at these interfaces depend on the conformational regularity of the organic polymer deposited on the metal substrate. Using ab-initio quantum chemical calculations based on density functional theory (DFT) and heterodyne vibrational sum frequency generation (HD-VSFG) measurements, we show that inducing regio-randomness into the organic polymer modifies the intensity of interfacial electronic states, level of hybridization, density of interfacial charge transfer and the electronic wave function of the material. We present the HD-VSFG responses of the metal/P3HT heterojunctions containing both regio-regular and regio-random P3HT structures and show that the amount of non-resonant signal is closely related to the level of the spontaneous charge transfer at the interface. Thus, by measuring the non-resonant response of the metal/P3HT heterojunctions, the level of spontaneous charge transfer at the interface can be determined.