The Electronic and Adsorption Structures of 2-Mercaptoethanol and Thioglycolic Acid on the Ge(100) Surface

• Published in: Bulletin of the Korean Chemical Society 2015, 36(10), , pp.2440-2445
• Main Author: Lee, Hangil
• Format: Article
• Language: English
• Subjects: Density functional calculations; Functional group selectivity; High-resolution photoemission spectroscopy; Molecular adsorption; 화학
• ISSN: 1229-5949; 0253-2964; 1229-5949
• DOI: 10.1002/bkcs.10468

The work function change and the corresponding stable adsorption structures. (a) 0.15 ML thioglycolic acid (TGA), (b) 0.65 ML TGA, (c) 0.15 ML 2‐ME, and (d) 0.65 ML 2‐ME adsorbed on the Ge(100) surface. The adsorption selectivity of 2‐mercaptoethanol (2‐ME) and thioglycolic acid (TGA) was studied on the Ge(100)‐2×1 surface using high‐resolution photoemission spectroscopy (HRPES) and the corresponding density functional theory (DFT) calculations. HRPES analysis results indicated that an OH dissociated SH dissociation bonded structure at low coverage and an O‐dative bonded structure at high coverage are the stable adsorption structures of 2‐ME on the Ge(100) surface. In addition, a SH dissociated OB ‐dative bonded structure at low coverage and a S‐dative bonded structure at high coverage are reasonable adsorption structures of TGA on the Ge(100) surface. Through work function measurements, we also confirmed that the forms of the adsorption structures of 2‐ME and TGA can be determined by n‐type (dissociation‐bonded structure) and p‐type (dative‐bonded structure) properties. Moreover, the adsorption structures of 2‐ME and TGA on the Ge(100)‐2×1 surface were determined through DFT calculations, and the respective stable adsorption structures, transition‐state energy, and reaction pathways were obtained.