Hu Yuanyuan, Jiang Lang, Chen Qinjun, Guo Jing, Chen Zhuojun
Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education, School of Physics and Electronics , Hunan University , Changsha 410082 , China.
Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China.
J Phys Chem Lett. 2018 Jun 7;9(11):2869-2873. doi: 10.1021/acs.jpclett.8b01274. Epub 2018 May 17.
It is commonly accepted that gate dielectric dipoles can induce energetic disorder in organic field-effect transistors. However, convincing experimental evidence that directly demonstrate this effect are still in lack. In this work, we present a combined experimental and theoretical study to reveal this effect. We have investigated the temperature-dependent mobility of two rubrene single-crystal transistors with different polymer dielectrics. Model fittings of the data indicate there is higher energetic disorder in the device on dielectric with larger permittivity. Scanning Kelvin probe microscopy was then employed to directly characterize the density of tail states, which is correlated with energetic disorder, in the devices. The results further confirm that dielectric dipoles can increase energetic disorder in organic semiconductors.
人们普遍认为，栅极电介质偶极子会在有机场效应晶体管中引发能量无序。然而，仍缺乏直接证明这种效应的令人信服的实验证据。在这项工作中，我们开展了一项结合实验与理论的研究来揭示这种效应。我们研究了两个采用不同聚合物电介质的红荧烯单晶晶体管的温度依赖性迁移率。数据的模型拟合表明，在具有较大介电常数的电介质上的器件中存在更高的能量无序。随后，我们使用扫描开尔文探针显微镜直接表征器件中与能量无序相关的尾态密度。结果进一步证实，电介质偶极子会增加有机半导体中的能量无序。
