Pressure-Dependent Electronic and Structural Properties of MoS2 - Dr. Jung-Fu Lin
The direct optical band gap of the monolayer 2H-MoS2 increases by 11.7% from 1.85 eV to 2.08 eV up to 16 GPa. DFT calculations further show metallization at ~60 GPa.
Significance and Impact
This substantial reversible tunability of the electronic and vibrational property of the MoS2 family can be extended to other 2D TMDs. These results present an important advance toward controlling the band structure and optoelectronic properties of monolayer MoS2 via pressure, which has vital implications for enhanced device applications.
– PL and Raman measurements in a DAC;
– DFT calculations to reveal rich electronic structures
Pressure Modulated Photoluminescent Properties of 2H-MoS2.
Representative PL spectra show an increase in the band gap with increasing pressure and then the diminishing of the PL signals at ~16 GPa indicates a direct-to-indirect band gap shift. Theoretical prediction of the direct-to indirect band gap transition.
A. P. Nayak, T. Pandey, D. Voiry, J. Liu, S.T. Moran, A. Sharma, C. Tan, C.-H. Chen6, L.-J. Li, M. Chhowalla, J.-F. Lin, A. Singh, D. Akinwande, Pressure-Dependent Electronicand Structural Properties of the Molybdenum Disulfide Family, Nano Letters (2014).