有机纳米材料光电子轨道断层成像技术  

Photoemission Orbital Tomography for Organic Nanomaterials

作　　者：杨笑生 李培宁 张新亮[1,2] Yang Xiaosheng;Li Peining;Zhang Xinliang(Wuhan National Laboratory for Optoelectronics,School of Optical and Electronic Information,Huazhong University of Scienceand Technology,Wuhan 430074,Hubei,China;Optics Valley Laboratory,Wuhan 430074,Hubei,China)

机构地区：[1]华中科技大学光学与电子信息学院武汉光电国家研究中心,湖北武汉430074 [2]湖北光谷实验室,湖北武汉430074

出　　处：《中国激光》2023年第1期3-16,共14页Chinese Journal of Lasers

基　　金：国家重点研发计划(2021YFA1201500);湖北省自然科学基金杰出青年项目(2022CFA053);华中科技大学武汉光电国家研究中心创新基金。

摘　　要：光电子轨道断层成像是有机纳米材料研究中一种实验和理论相结合的技术,其核心是建立光电子角分布能谱和分子初始态轨道结构之间的直接联系。研究者通过较为简易的平面波近似,可以实现对表面共轭分子价带轨道角分辨光电子能谱的精确分析,从而研究它们的电学、光学和化学特性。介绍了光电子轨道断层成像技术的理论基础和实验手段,综述了近年来该技术在确定分子的几何结构、测量界面电学相互作用、获得时间分辨轨道图像等领域的诸多应用,并介绍了该技术结合超快激光等相关实验技术的最新进展。Significance Development of nanotechnology in the last few decades have witnessed the miniaturization of semiconductor devices and new challenges such as building a quantum computer using novel physical phenomena.On the fundamental level,however,many aspects in the understanding of physical properties at interfaces between materials are still in the exploration stage,and precise experimental and theoretical descriptions of complex surface structures are always difficult but crucial for practical applications.In the subfield of organic electronics that studies the solid-molecule interfaces,such as in organic light-emitting diode(OLED)displays or organic solar cells,the frontier orbitals of molecules are prime determinants of chemical,optical and electronic properties in the devices.For a long time,physicists and chemists have dreamed of experimentally imaging molecular orbitals,which contain information on the spatial distribution of the electrons at a certain energy.To date,experimental methods for this purpose include femtosecond laser spectroscopy and scanning probe microscopy,which have gained widespread interest but also have some limitations.For example,high-order harmonic generation process based on ultrashort laser pulses is limited to the study of simple gas-phase molecules,and methods based on scanning probe microscopy require extremely low temperature to prevent molecular diffusion.In comparison,photoemission orbital tomography(POT)is based on angle-resolved photoemission spectroscopy(ARPES)at room temperature with less restricted experimental conditions.As a combined experimental and theoretical technique,POT focuses on establishing a direct link between the photoelectron angular distribution and the initial-state molecular orbital structure.By using a relatively simple plane-wave approximation,one can perform accurate analysis of the angle-resolved photoemission spectra forπ-conjugated molecules on surface to study their respective properties.Progress Since POT deals with the photoemission experiment

关 键 词：光谱学 有机纳米材料 光电子能谱 固体-分子界面 分子轨道 断层成像 超快泵浦-探测光谱 

分 类 号：O433[机械工程—光学工程]