| Literature DB >> 26135798 |
Saifeng Zhang1, Ningning Dong1, Niall McEvoy2, Maria O'Brien2,3, Sinéad Winters2,3, Nina C Berner2, Chanyoung Yim2,3, Yuanxin Li1, Xiaoyan Zhang1, Zhanghai Chen4, Long Zhang1, Georg S Duesberg2,3, Jun Wang1,5.
Abstract
The optical nonlinearity of WS2 and MoS2 monolayer and few-layer films was investigated using the Z-scan technique with femtosecond pulses from the visible to the near-infrared range. The nonlinear absorption of few- and multilayer WS2 and MoS2 films and their dependences on excitation wavelength were studied. WS2 films with 1-3 layers exhibited a giant two-photon absorption (TPA) coefficient as high as (1.0 ± 0.8) × 10(4) cm/GW. TPA saturation was observed for the WS2 film with 1-3 layers and for the MoS2 film with 25-27 layers. The giant nonlinearity of WS2 and MoS2 films is attributed to a two-dimensional confinement, a giant exciton effect, and the band edge resonance of TPA.Entities:
Keywords: MoS2; WS2; Z-scan; saturable absorption; two-dimensional semiconductors; two-photon absorption
Year: 2015 PMID： 26135798 DOI： 10.1021/acsnano.5b03480
Source DB: PubMed Journal: ACS Nano ISSN： 1936-0851 Impact factor: 15.881