Intricate Resonant Raman Response in Anisotropic ReS2

• DOI: 10.1021/acs.nanolett.7b01463
• Publication Date: 2017-08-18T19:59:38Z
• Authors: Amber McCreary; Jeffrey R. Simpson; Yuanxi Wang; Daniel Rhodes; Kazunori Fujisawa; Luis Balicas; Madan Dubey; Vincent H. Crespi; Mauricio Terrones; Angela R. Hight W...
• Keywords: 02 engineering and technology; 0210 nano-technology

The strong in-plane anisotropy of rhenium disulfide (ReS2) offers an additional physical parameter that can be tuned for advanced applications such as logic circuits, thin-film polarizers, and polarization-sensitive photodetectors. ReS2 also presents advantages optoelectronics, it is both a direct-gap semiconductor few-layer thicknesses (unlike MoS2 or WS2) stable in air black phosphorus). Raman spectroscopy one the most powerful characterization techniques to nondestructively sensitively probe fundamental photophysics 2D material. Here, we perform thorough study resonant response 18 first-order phonons at various layer crystal orientations. Remarkably, discover that, opposed general increase intensity all modes excitonic transitions, each behave differently relative other function laser excitation, thickness, orientation manner highlights importance electron-phonon coupling ReS2. In addition, correct unrecognized error calculation optical interference enhancement signal transition metal dichalcogenides on SiO2/Si substrates has propagated through reports. For ReS2, this correction critical properly assessing behavior. We implemented perturbation approach calculate frequency-dependent intensities based first-principles demonstrate despite neglect effects, useful trends monolayer bulk different energies accurately captured. Finally, phonon dispersion calculated from used address possible origins unexplained peaks observed spectra, infrared-active modes, defects, second-order processes.