A Large Anisotropic Enhancement of the Charge Carrier Mobility of Flexible Organic Transistors with Strain: A Hall Effect and Raman Study
A Large Anisotropic Enhancement of the Charge Carrier Mobility of Flexible Organic Transistors with Strain: A Hall Effect and Raman Study
复制标题
应变对柔性有机晶体管电荷载流子迁移率的大各向异性增强：霍尔效应和拉曼研究
DOI：
10.1002/advs.201901824
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发表时间：
2019-11-13
期刊：
影响因子：
15.1
通讯作者：
Podzorov, Vitaly
中科院分区：
文献类型：
--
作者：
Choi, Hyun Ho;Yi, Hee Taek;Podzorov, Vitaly
利用半导体中固有的迁移率-应变关系对于在高性能柔性电子产品中实现应变工程应用至关重要。在这里，报告了有机半导体的霍尔效应和拉曼光谱作为单轴机械应变的函数的测量结果。这项研究揭示了单晶红荧烯晶体管的本征（无陷阱）电荷载流子迁移率在应变下的非常强、各向异性和可逆的调制，表明有机电路的有效迁移率只需 1% 的压缩应变即可增强高达 100%。一致地，拉曼光谱揭示了红荧烯的低频拉曼模式在压缩（拉伸）应变下向更高（更低）频率的系统转变，这表明晶体中的热分子无序随着应变的减少（增强）。这项研究奠定了有机电子学中应变工程的基础，并增进了对有机半导体中载流子迁移率、低频振动模式、应变和分子无序之间关系的认识。
Utilizing the intrinsic mobility-strain relationship in semiconductors is critical for enabling strain engineering applications in high-performance flexible electronics. Here, measurements of Hall effect and Raman spectra of an organic semiconductor as a function of uniaxial mechanical strain are reported. This study reveals a very strong, anisotropic, and reversible modulation of the intrinsic (trap-free) charge carrier mobility of single-crystal rubrene transistors with strain, showing that the effective mobility of organic circuits can be enhanced by up to 100% with only 1% of compressive strain. Consistently, Raman spectroscopy reveals a systematic shift of the low-frequency Raman modes of rubrene to higher (lower) frequencies with compressive (tensile) strain, which is indicative of a reduction (enhancement) of thermal molecular disorder in the crystal with strain. This study lays the foundation of the strain engineering in organic electronics and advances the knowledge of the relationship between the carrier mobility, low-frequency vibrational modes, strain, and molecular disorder in organic semiconductors.