About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
2D Materials – Preparation, Properties, Modeling & Applications
|
| Presentation Title |
Ultrahigh Purity Tungsten Diselenide: Thermodynamics, Synthesis and Characterization |
| Author(s) |
Katayun Barmak |
| On-Site Speaker (Planned) |
Katayun Barmak |
| Abstract Scope |
2D layered transition metal dichalcogenides (TMDs) are promising candidates for electronics and optoelectronics applications. They also provide a platform for realizing novel correlated quantum states. However, defects impact the desired properties of TMDs, limiting functionality and performance. To reduce defect densities in TMDs, knowledge of defect thermodynamics is foundational to guiding their synthesis. The intrinsic defect formation energies in WSe2 were determined by density functional theory (DFT) and then augmented with elemental chemical potential functions to determine temperature and pressure-dependent formation energies. The calculated thermodynamic equilibrium densities are several orders of magnitude below reported defect densities, thereby establishing that current synthesis methods are either kinetically limited or impurity dominated. Our improved flux growth approaches have now dramatically reduced defect densities in WSe2, leading to record-setting mobilities in WSe2 and enabling observation of correlated low-density states. Defect characterization using STM and conductive AFM provided real-time feedback to refine the growth processes. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Electronic Materials, Nanotechnology, Other |