The WS2 quantum dot: preparation, characterization and its optical limiting effect in polymethylmethacrylate.
Due to the matching surface energy, WS2 quantum dots (QDs) can be obtained through direct liquid exfoliation in N-methyl-2-pyrrolidone rather than an ethanol and water mixture. Ultra-small WS2 QDs with a diameter of 2.4 nm are fabricated by an ultrasound method followed by high speed centrifugation up to 10 000 rpm. An excellent nonlinear optical (NLO) property of the WS2 QD/ polymethylmethacrylate (PMMA) composite for the nanosecond pulsed laser at both 532 and 1064 nm has been measured. Results illustrate the lower onset thresholds (F ON ), lower optical limiting thresholds (F OL ), and higher two-photon absorption coefficient (β) with respect to a higher concentration of embedded WS2 QDs into the PMMA solid state matrix for both 532 and 1064 nm.
Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, People's Republic of China. The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, People's Republic of China.
Hui
H
Long
Lili
L
Tao
Chun Pang
CP
Chiu
Chun Yin
CY
Tang
Kin Hung
KH
Fung
Yang
Y
Chai
Yuen Hong
YH
Tsang