Thermally Activated Reactions of Phenol at the Ge(100)‑2 × 1 Surface

Organic functionalization of semiconductor surfaces may be utilized to couple the properties of semiconductor materials with organic molecules. In this work, the adsorption and thermal reactions of phenol on the Ge(100)-2 × 1 surface were studied. A combination of multiple internal reflection Fourier transform infrared (MIR-FTIR) spectroscopy under ultrahigh vacuum (UHV) conditions and density functional theory (DFT) calculations was used to elucidate the surface chemical reactions of phenol. While phenol initially chemisorbs on Ge(100)-2 × 1 at 300 K via O–H dissociation to form phenoxy (C₆H₅O*), annealing to 573 K transforms the adsorbate into phenyl (C₆H₅*). A sequential reaction pathway for the migration of oxygen into substrate and formation of phenyl is suggested, which requires significant thermal activation and yields slight exothermicity.