Chimie des Interactions Plasma-Surface, University of Mons (UMONS), 20 Place du Parc, 7000 Mons, Belgium.
Elettra Sincrotrone Trieste, Strada Statale 14 km 163.5, I-34149 Trieste, Italy.
J Chem Phys. 2017 Dec 28;147(24):244704. doi: 10.1063/1.5008800.
The interaction between 2,2'-bithiophene-5-carboxylic acid (PT2) sublimed under ultra-high vacuum conditions and anatase (101) and rutile (110) TiO single crystal surfaces is investigated by studying the electronic spectral density near the Fermi level with synchrotron-based spectroscopy. The experimental results are compared to density functional theory calculations of the isolated PT2 molecule and of the molecule adsorbed on an anatase TiO (101) cluster. The relative concentrations of Ti, C, and S atoms indicate that the adsorbed molecule remains intact upon deposition, which is typical of a Stranski-Krastanov growth mode. The analysis of the O1s spectrum suggests a predominant bidentate geometry of the adsorption with both rutile and anatase surfaces, as supported by previous theoretical simulations. It is also theoretically and experimentally demonstrated that the PT2 adsorption causes the appearance of new electronic states in the gap near the TiO valence band. A pinning effect of the LUMO level of the dye is also theoretically predicted.
在超高真空条件下升华的 2,2'-联噻吩-5-羧酸（PT2）与锐钛矿（101）和金红石（110）TiO 单晶表面的相互作用通过基于同步加速器的光谱学研究费米能级附近的电子光谱密度来研究。实验结果与孤立 PT2 分子和吸附在锐钛矿 TiO（101）团簇上的分子的密度泛函理论计算进行了比较。Ti、C 和 S 原子的相对浓度表明，吸附分子在沉积后保持完整，这是 Stranski-Krastanov 生长模式的典型特征。O1s 光谱的分析表明，吸附具有两种 TiO 表面的桥联二齿几何形状，这得到了先前理论模拟的支持。理论和实验也证明，PT2 吸附导致 TiO 价带附近间隙中出现新的电子态。染料的 LUMO 能级的钉扎效应也在理论上进行了预测。
