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A type-II GaSe/HfS2 van der Waals heterostructure as promising photocatalyst with high carrier mobility
- Source :
- Applied Surface Science. 534:147607
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- In this paper, the electronic, optical, and photocatalytic properties of GaSe/HfS2 heterostructure are studied via first-principles calculations. The stability of the vertically stacked heterobilayers is validated by the binding energy, phonon spectrum, and ab initio molecular dynamics simulation. The results reveal that the most stable GaSe/HfS2 heterobilayer retains a type-II alignment with an indirect bandgap 1.40 eV. As well, the results also show strong optical absorption intensity in the studied heterostructure (1.8 × 105 cm−1). The calculated hole mobility is 1376 cm2 V−1 s−1, while electron mobility reaches 911 cm2 V−1 s−1 along the armchair and zigzag directions. By applying an external electric field, the bandgap and band offset of the designed heterostructure can be effectively modified. Remarkably, a stronger external electric field can create nearly free electron states in the vicinity of the bottom of the conduction band, which induces indirect-to-direct bandgap transition as well as a semiconductor-to-metal transition. In contrast, the electronic properties of GaSe/HfS2 heterostructure are predicted to be insensitive to biaxial strain. The current work reveals that GaSe/HfS2 heterostructure is a promising candidate as a novel photocatalytic material for hydrogen generation in the visible range.
- Subjects :
- Free electron model
Electron mobility
Materials science
Condensed matter physics
Phonon
Band gap
Binding energy
General Physics and Astronomy
Heterojunction
02 engineering and technology
Surfaces and Interfaces
General Chemistry
Condensed Matter::Mesoscopic Systems and Quantum Hall Effect
010402 general chemistry
021001 nanoscience & nanotechnology
Condensed Matter Physics
01 natural sciences
Band offset
0104 chemical sciences
Surfaces, Coatings and Films
Condensed Matter::Materials Science
Electric field
0210 nano-technology
Subjects
Details
- ISSN :
- 01694332
- Volume :
- 534
- Database :
- OpenAIRE
- Journal :
- Applied Surface Science
- Accession number :
- edsair.doi...........d0464caa1dfaba73e17c47583000aac4