Choi Hyun Ho, Yi Hee Taek, Tsurumi Junto, Kim Jae Joon, Briseno Alejandro L, Watanabe Shun, Takeya Jun, Cho Kilwon, Podzorov Vitaly
Department of Physics Rutgers University Piscataway NJ 08854 USA.
School of Materials Science and Engineering and Engineering Research Institute Gyeongsang National University Jinju 52828 Korea.
Adv Sci (Weinh). 2019 Nov 13;7(1):1901824. doi: 10.1002/advs.201901824. eCollection 2020 Jan.
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.
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器件中实现应变工程应用至关重要。在此，报道了作为单轴机械应变函数的有机半导体的霍尔效应和拉曼光谱测量。这项研究揭示了单晶红荧烯晶体管的本征（无陷阱）电荷载流子迁移率随应变的非常强烈、各向异性且可逆的调制，表明仅1%的压缩应变就能使有机电路的有效迁移率提高多达100%。一致地，拉曼光谱显示红荧烯的低频拉曼模式随着压缩（拉伸）应变向更高（更低）频率的系统位移，这表明晶体中热分子无序随应变而减少（增强）。这项研究奠定了有机电子学中应变工程的基础，并推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。
