AVS 62nd International Symposium & Exhibition
    2D Materials Focus Topic Tuesday Sessions
       Session 2D+EM+NS+SS+TF-TuM

Invited Paper 2D+EM+NS+SS+TF-TuM12
Nonlinear Optical Spectroscopy of 2D Semiconductor Monolayers

Tuesday, October 20, 2015, 11:40 am, Room 212C

Session: Optical and Optoelectronic Properties of 2D Materials
Presenter: Xiaobo Yin, University of Colorado Boulder
Correspondent: Click to Email

Transition metal dichalcogenide (TMDC) monolayers have recently emerged as an important class of two-dimensional semiconductors with potential for electronic and optoelectronic devices. Unlike semi-metallic graphene, layered TMDCs have a sizeable bandgap. More interestingly, when thinned down to a monolayer, TMDCs transform from indirect-bandgap to direct-bandgap semiconductors, exhibiting a number of intriguing optical phenomena such as valley-selective circular dichroism, doping-dependent charged excitons and strong photocurrent responses. Using nonlinear optical spectroscopy, we probe experimentally the evidence of a series of excitonic dark states as well as structural symmetry in single-layer WS2 and MoS2.