Preparation and third-order optical nonlinearity of self-assembled chitosan/CdSe-ZnS core-shell quantum dots multilayer films.
The self-assembled chitosan CdSe quantum dots (QDs) and chitosan CdSe-ZnS core-shell QDs films have been prepared by using layer-by-layer electrostatic technique. The well-ordered nanostructure and the layer-by-layer deposition of the QDs are revealed by AFM and exciton absorption spectra, respectively. The optical nonlinearity of the composite films were studied by using Z-scan technique with femtosecond pulses at the wavelength of 790 nm, the value of third-order susceptibility of core-shell QDs are measured to be about 1.1 x 10(-8) esu, which is about 200% larger than that of CdSe QDs of 5.3 x 10(-9) esu. This has potential applications in all-optical switches in optical information processing.
School of Resource and Environmental Science, Department of Physics and Center for Nanoscience & Nanotechnology Research, and College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
Xiaohui
X
Wang
Yumin
Y
Du
Sha
S
Ding
Ququan
Q
Wang
Guiguang
G
Xiong
Min
M
Xie
Xincheng
X
Shen
Daiwen
D
Pang