Refine
Language
- English (10)
Is part of the Bibliography
- yes (10)
Keywords
- Artof (2)
- Electron spectroscopy (2)
- Synchrotron (2)
- Time of flight (2)
- photoelectron spectroscopy (2)
- ARPES (1)
- Energy resolution (1)
- Wide angle (1)
- catalysis (1)
- complexes (1)
- dichalcogenides (1)
- dynamics (1)
- electron spectroscopy (1)
- electronic-structure (1)
- energy resolution (1)
- hydrogen evolution reaction (1)
- ion migration (1)
- iron(II) (1)
- l-edge xas (1)
- laser illumination (1)
- lead halide perovskite (1)
- molecular-structure (1)
- phase separation (1)
- phase transitions (1)
- probe (1)
- spectra (1)
- spin-state (1)
- stability (1)
- synchrotron (1)
- time of flight (1)
- water (1)
- wide angle (1)
Visible light is shown to create a transient metallic S-Mo-S surface layer on bulk semiconducting p-doped indirect-bandgap 2H-MoS2. Optically created electron-hole pairs separate in the surface band bending region of the p-doped semiconducting crystal causing a transient accumulation of electrons in the surface region. This triggers a reversible 2H-semiconductor to 1T-metal phase-transition of the surface layer. Electron-phonon coupling of the indirect-bandgap p-doped 2H-MoS2 enables this efficient pathway even at a low density of excited electrons with a distinct optical excitation threshold and saturation behavior. This mechanism needs to be taken into consideration when describing the surface properties of illuminated p-doped 2H-MoS2. In particular, light-induced increased charge mobility and surface activation can cause and enhance the photocatalytic and photoassisted electrochemical hydrogen evolution reaction of water on 2H-MoS2. Generally, it opens up for a way to control not only the surface of p-doped 2H-MoS2 but also related dichalcogenides and layered systems. The findings are based on the sensitivity of time-resolved electron spectroscopy for chemical analysis with photon-energy-tuneable synchrotron radiation.