Octithiophene on Cu(111) and Au(111): Formation and Electronic Structure of Molecular Chains and Films
Octithiophene on Cu(111) and Au(111): Formation and Electronic Structure of Molecular Chains and Films
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Cu(111) 和 Au(111) 上的奥噻吩：分子链和薄膜的形成和电子结构
DOI：
10.1166/jnn.2012.5860
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Masato Nakaya nad Tomonobu Nakayama
中科院分区：
文献类型：
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作者：
Toshiyuki kakudate;Shigeru Tsukamoto osamu Kubo;Masato Nakaya nad Tomonobu Nakayama
利用扫描隧道显微镜（STM）和光谱学（STS）研究了八噻吩（8T）分子在Cu（111）和Au（111）表面的吸附和电子结构。我们发现8T分子在两个表面上的吸附行为有很大的不同。在吸附的初始阶段，8T分子以分子链的形式稳定在Cu平台上（111），而在Au平台上（111）既没有观察到这种链状结构，也没有观察到孤立的8T分子。通过增加吸附分子的数量，在Cu（111）上形成无序的单层膜，而在Au（111）上形成有序的单层膜。利用偏置STM图像和STS光谱进行光谱研究，并将数据与理论计算进行比较，发现Cu（111）上分子链上8T分子的电子性质与独立8T分子的电子性质不同，而Au（111）上单层膜中的8T分子保持了独立8T分子的原始特征。本研究表明，8T分子在Cu（111）上的吸附导致在费米能级附近形成吸附诱导态。
Adsorption and electronic structure of octithiophene (8T) molecules on Cu(111) and Au(111) surfaces are investigated using scanning tunneling microscopy (STM) and spectroscopy (STS) at room temperature. We find a large difference in adsorption behavior of 8T molecules on the two surfaces. At the initial stage of adsorption, 8T molecules are stabilized in the form of molecular chain on a terrace of Cu(111), whereas neither such chain structure nor isolated 8T molecules have been observed on a terrace of Au(111). By increasing the amount of adsorbed molecules, a disordered monolayer film is formed on Cu(111) while a well-ordered monolayer film is formed on Au(111). From the spectroscopic investigations using bias-dependent STM images and STS spectra and by comparing the data with theoretical calculations, it is found that the electronic property of 8T molecules in the molecular chain on Cu(111) is different from that of a free-standing 8T molecule while that in the monolayer film on Au(111) keeps original character of the free-standing 8T molecule. The present study shows that adsorption of 8T molecules on Cu(111) results in a formation of adsorption-induced states near the Fermi level.