石墨烯纳米卷的各向异性光响应  

Anisotropic Optical Response of Graphene Nanoscrolls

作　　者：尹煜 刘朝贵 张书涵 周雷 刘安航 万晨宇 汪海潮 江涛[1,2] 黄迪[1] 王占山[1,2] 程鑫彬[1,2] Yin Yu;Liu Chaogui;Zhang Shuhan;Zhou Lei;Liu Anhang;Wan Chenyu;Wang Haichao;Jiang Tao;Huang Di;Wang Zhanshan;Cheng Xinbin(Institute of Precision Optical Engineering,MOE Key Laboratory of Advanced Micro-Structured Materials,Shanghai Frontiers Science Center of Digital Optics,Shanghai Professional Technical Service Platform for Full-Spectrum and High-Performance Optical Thin Film Devices and Applications,School of Physics Science and Engineering,Tongji University,Shanghai 200092,China;Shanghai Research Institute of Intelligent Autonomous Systems,Tongji University,Shanghai 201210,China)

机构地区：[1]同济大学精密光学工程技术研究所,先进微结构材料教育部重点实验室,上海市数字光学前沿科学研究基地,上海市全光谱高性能光学薄膜器件与应用专业技术服务平台,物理科学与工程学院,上海200092 [2]同济大学上海自主智能无人系统科学中心,上海201210

出　　处：《中国激光》2024年第18期300-308,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(62305249,62175188,61925504,6201101335,62020106009,62192770,62192772,61621001);上海市科学与技术委员会项目(23190712300,23ZR1465800);中央高校基本科研业务费专项资金(13702150100)。

摘　　要：单层石墨烯独特的能带结构赋予了其宽谱响应、高迁移率、超快响应等优异特性,这使得其在光电技术领域备受关注。然而,石墨烯具有高对称性,缺乏各向异性的光响应,这一点限制了其在偏振探测、量子通信、光学传感等领域的应用。本课题组利用石墨烯卷曲制备石墨烯纳米卷,破缺了石墨烯原有的高对称性,实现了各向异性的光响应。通过优化石墨烯纳米卷的制备和表征工艺,在拉曼与非线性过程中观察到了显著的各向异性光响应,说明石墨烯纳米卷形成过程破缺了石墨烯原有的晶格对称性。利用上述对称性破缺效应,制备了基于石墨烯纳米卷的各向异性光电器件,其光电流偏振比为0.33。此外,该器件还呈现出空间异质光电响应特性,结合拉曼光谱成像、近场显微成像技术推断该效应来源于缺陷、应力和掺杂分布等。本研究对于理解石墨烯纳米卷的各向异性光响应及其在光电器件中的潜在应用具有重要意义。Objective The distinct band structure of monolayer graphene endows it with exceptional properties such as broadband response,high carrier mobility,and ultrafast response,thus rendering graphene highly promising in the field of optoelectronics.However,graphene exhibits isotropic optical responses owing to its high symmetry,which limits its application in devices for polarization detection,quantum communication,and optical sensing.This study proposes methods for the spontaneous curling of graphene to reduce its dimensionality and for forming graphene nanoscrolls,thereby breaking the high symmetry of graphene and achieving anisotropic optical responses.By optimizing the preparation and characterization processes of graphene nanoscrolls,we observed significant anisotropic optical responses in both the Raman and nonlinear processes,which indicates a change in the original latticestructure symmetry of graphene during curling,thus resulting in lattice-symmetry breaking in the graphene nanoscrolls.By applying symmetry-breaking effects,we prepared an optoelectronic device based on graphene nanoscrolls with anisotropic responses and confirmed a photocurrent anisotropic ratio of 0.33.We further observed spatially dependent photocurrent responses in the device by comparing Raman spectra and near-field microscopy imaging results.We inferred that this spatial heterogeneity originates from defects,strain,and doping.This study is important for understanding the anisotropic properties of graphene nanoscrolls and their applications in optoelectronic devices.Methods First,an appropriate monolayer of graphene was prepared on a silicon-dioxide layer via mechanical exfoliation.Subsequently,an isopropanol(IPA)aqueous solution(volume ratio of IPA to water is 1∶3)was deposited onto the graphene monolayer to induce spontaneous curling,thereby resulting in graphene nanoscrolls.We employed various spectroscopic and microscopic techniques to comprehensively characterize the anisotropic structure and optical response of the nanoscrolls.Addi

关 键 词：石墨烯纳米卷 各向异性 拉曼 二次谐波 光电响应 

分 类 号：O437[机械工程—光学工程]