铜氧化层上钒氧酞菁分子的吸附构型及组装结构  

Adsorption configuration and assembly structure of vanadyl phthalocyanine molecule on copper oxide layer

作　　者：彭兰沁 李小雨 幸运 赵涵 邓炎滔 于迎辉 Peng Lan-Qin;Li Xiao-Yu;Xing Yun;Zhao Han;Deng Yan-Tao;Yu Ying-Hui(Faculty of Physics,Hubei University,Wuhan 430062,China)

机构地区：[1]湖北大学物理学院,武汉430062

出　　处：《物理学报》2024年第12期118-125,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:21872171);湖北省自然科学基金(批准号:2019CFB779)资助的课题。

摘　　要：近年来,有机功能分子的调控因其在提高纳米光电器件内部载流子迁移率方面的突出贡献,已逐渐成为材料科学的热门领域之一.本文利用低温扫描隧道显微镜系统地研究了钒氧酞菁(VOPc)分子在干净Cu(110)和铜氧化层表面的吸附构型和组装结构.在Cu(110)表面,初始时VOPc分子孤立吸附且氧原子向上和向下的构型共存.而在CuO-(2×1)表面,VOPc分子在初始时形成扩展的分子链,随后组装为有序的分子膜,在分子膜中两种吸附构型仍然共存且随机排布.在Cu_(5)O_(6)-c(6×2)表面,初始时VOPc分子的两种构型共存且形成无序结构.在覆盖度接近一个单层时,结构有序的组装分子膜逐渐形成,此时主要采用氧原子向上的分子构型,因偶极相互作用,随后的分子层生长遵循两种分子构型交替堆垛.研究还发现当Cu(110)表面上两种氧化结构共存时,第2层分子更倾向于吸附在Cu_(5)O_(6)-c(6×2)表面担载的分子膜上,主要是由分子层间的偶极相互作用导致的.本研究表明金属表面的氧化层在改变分子吸附构型和组装结构方面的重要性,可能将影响电子器件制造中分子膜中的电荷输运过程.In recent years,regulating organic functional molecule has gradually received much attention in the field of materials due to its significant contribution in improving the charge carrier mobility of nanometer optoelectronic device.Molecular configuration and assembly structure of vanadyl phthalocyanine(VOPc)are systemically investigated on pristine and oxidized Cu(110)surface by using low temperature scanning tunneling microscopy.In the initial deposition stage,two molecular adsorption configurations,referring to O-up and Odown,are randomly distributed on the pristine Cu(110)surface.By oxidizing Cu(110)at different oxygen atmospheres and substrate temperatures,two different copper oxide structures are obtained,i.e.CuO-(2×1)and Cu5O6-c(6×2).The VOPc molecules are then deposited on both surfaces via thermal evaporation.For the CuO-(2×1)surface,contrastly,extended molecular chains form in the initial adsorption and subsequently the VOPc molecules assemble into an ordered molecular film involving both configurations.The VOPc molecules shows two packing orientations with a rotation angle of about 36°relative to each other.On Cu_(5)O_(6)-c(6×2),the Odown and O-up molecules are isolatedly adsorbed at the initial coverage.As the coverage increases,molecular assembly film gradually forms a parallelogram-shaped unit cell that involves only the O-up molecules.The molecular film exhibits two distinct molecular orientations with a rotation angle of about 42°relative to each other.The dipole-dipole interaction drives the configuration transition from the O-up configuration to O-down configuration.The O-down VOPc molecules of the second layer tend to be adsorbed on the molecular membrane supported by the Cu_(5)O_(6)-c(6×2)surface.The dipole-dipole interaction between neighboring molecular layers may be responsible for the preferable adsorption of the second-layered molecules.This study suggests the importance of surface oxidization in modifying configurations and orbital distributions of adsorbed molecules that can affec

关 键 词：钒氧酞菁 铜氧化层 扫描隧道显微镜 分子组装 

分 类 号：O647.3[理学—物理化学]