有机半导体perylene和tetracene在Ag(110)表面上有序薄膜的结构与电子态研究

利用紫外光电子能谱(UPS)和低能电子衍射(LEED)对银(110)表面上perylene与tetracene的生长进行了研究.LEED的结果表明：一个分子单层的perylene在银(110)表面上会形成C(6×2)的有序结构；一个分子单层的tetracene，观察到的则是C(4×2)的有序结构.根据UPS的测量，与perylene分子轨道有关的4个特征峰分别位于Frimi能级以下35，48，64和85eV处，与tetracene分子轨道有关的4个特征峰的结合能分别为3．4，49，59和94eV.角分辨紫外光电子能谱(ARUPS)的测量表明，表面附近的perylene和tetracene分子平面平行于银衬底表面，tetracene分子的长轴可以确定沿［110］晶向. 关键词： 有机半导体材料 紫外光电子能谱 结构和电子结构

The structure and electronic state of the ordered thin film of perylene and tetracene on Ag(110) surface

The growth of perylene and tetracene on Ag (110) has been studied by the ultraviolet photoemission spectroscopy (UPS) and low-energy electron diffraction (LEED). The LEED results illustrate that an ordered C(6×2) structure can be observed when the thickness of perylene is about one monolayer (thickness of 03n m), and an ordered C (4×2) structure for tetracene with a thickness of one monolayer. From the measurements of UPS, four emission features of perylene are located at 35, 48, 64 and 85eV below the Fermi level respectively, and f our characteristic peaks, for tetracene, are located at 34, 49, 59 and 9 4 eV below the Fermi level. The angle_resolved ultraviolet photoemission spectro scopy measurements show that both perylene and tetracene near the interface are parallel to the substrate, the tetracene molecule is along ［110］ direction.