Tuning nonlinear optical absorption properties of WS2nanosheets

Hui Long, Lili Tao, Chun Yin Tang, Bo Zhou, Yuda Zhao, Longhui Zeng, Siu Fung Yu, Shu Ping Lau, Yang Chai, Yuen Hong Tsang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

41 Citations (Scopus)

Abstract

To control the optical properties of two-dimensional (2D) materials is a long-standing goal, being of both fundamental and technological significance. Tuning nonlinear optical absorption (NOA) properties of 2D transition metal dichalcogenides in a cost effective way has emerged as an important research topic because of its possibility to custom design NOA properties, implying enormous applications including optical computers, communications, bioimaging, and so on. In this study, WS2with different size and thickness distributions was fabricated. The results demonstrate that both NOA onset threshold, FON, and optical limiting threshold, FOL, of WS2under the excitation of a nanosecond pulsed laser can be tuned over a wide range by controlling its size and thickness. The FONand FOLshow a rapid decline with the decrease of size and thickness. Due to the edge and quantum confinement effect, WS2quantum dots (2.35 nm) exhibit the lowest FON(0.01 J cm-2) and FOL(0.062 J cm-2) among all the samples, which are comparable to the lowest threshold achieved in graphene based materials, showing great potential as NOA materials with tunable properties.
Original languageEnglish
Pages (from-to)17771-17777
Number of pages7
JournalNanoscale
Volume7
Issue number42
DOIs
Publication statusPublished - 14 Nov 2015

ASJC Scopus subject areas

  • Materials Science(all)

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