摘要
通过有机分子束沉积法和超高真空-低温扫描隧道显微镜研究了非手性的萘酞菁(H_(2)Pc)在Cd(0001)表面的手性特征和生长机理.研究发现:在极低的覆盖度下,每个分子都沿Cd(0001)衬底的晶向排列.随着分子的聚集,分子的叶瓣和衬底的晶向不是一致的,存在大约8°的偏差.在0.8 ML(定义1 ML为在第2层出现之前能够完全覆盖整个衬底表面的H_(2)Pc覆盖度)时,由于与衬底的不对称电荷转移,M型分子(定义M型分子叶瓣与衬底晶向成8°夹角)表现出明显的手性特征.随着覆盖率的进一步提高,H_(2)Pc分子的亚单层分子从平躺表面吸附转变为倾斜三角吸附,同时表现出不同的手性特征.在分子的第2层中,H_(2)Pc分子表现出倾斜的吸附.
Chiral feature and multilayer growth mechanism of achiral naphthalene phthalocyanine(H_(2)Pc)on the surface of Cd(0001)were studied by organic molecular beam deposition and ultrahigh vacuum-cryogenic scanning tunneling microscope.It has been found in the study that,under extremely low coverage,each molecule is aligned along the crystal orientation of the Cd(0001)substrate.With the aggregation of molecules,the lobes of the molecules and the crystal orientation of the substrate are not the same,there are about 8°deviation.At 0.8 ML,the misoriented molecules exhibit obvious chiral characteristics due to asymmetric charge transfer with the substrate.With the further increase of coverage,the sub-monolayer of H_(2)Pc molecules changed from lying adsorption to the characteristics of trilobate,while showing different chiral characteristics.In the second layer of molecules,the H_(2)Pc molecules exhibit tilted adsorption.Our findings provide a powerful reference for the preparation of large-scale H_(2)Pc molecular thin films.
作者
马朝科
石明霞
孙凯
陶敏龙
王俊忠
谷云高
MA Chaoke;SHI Mingxia;SUN Kai;TAO Minlong;WANG Junzhong;GU Yungao(School of Physical Science and Technology,Southwest University,Chongqing 400715,China;College of Mechanical and Electrical Engineering,Handan College,Handan Hebei 056002,China)
出处
《西南师范大学学报（自然科学版）》
CAS
2021年第11期23-30,共8页
Journal of Southwest China Normal University(Natural Science Edition)
基金
国家自然科学基金(11874304,11574253,11604269,11674323,11804282,21673220).
