| AVS 61st International Symposium & Exhibition | |
| 2D Materials Focus Topic | Wednesday Sessions |
| Session 2D+AS+EM+MI+MN+NS+TF-WeA |
| Session: | Properties of 2D Materials |
| Presenter: | Danilo Romero, University of Maryland, College Park |
| Authors: | D. Romero, University of Maryland, College Park M. Watson, Towson University J.R. Simpson, Towson University H. Berger, Ecole Polytechnique Federale de Lausanne, Switzerland A.R. Hight Walker, NIST |
| Correspondent: | Click to Email |
We investigate the effects dimensionality on the electronic properties through the optical spectra of the transition-metal dichalcogenides 2H-TaSe2 and 1T-TaSe2, and 1T-TaS2. In bulk, these materials exhibit electronic states from Mott insulator, commensurate and incommensurate charge-density phases, and superconducting ground state as function of temperature. We explore the evolution of these properties as the materials approach a few layers, achieved via mechanical exfoliation of bulk single-crystals. Raman and photoluminescence spectroscopy of 2H-TaSe2 and 1T-TaSe2, and 1T-TaS2, carried out over a wide-range of temperature, were used as a probe of the change of the electronic properties from the bulk to single-layer phases of the materials. Comparison of the phonon and excitonic transitions as a function of temperature and dimensionality will be presented.