Fluorescence Enhancement of ZnS Nanocrystals via Ultraviolet Irradiation

Abstract:

ZnS nanocrystals were prepared via chemical precipitation method and characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) and photoluminescence (PL) spectra. The results indicated that the ZnS nanocrystals have cubic zinc blende structure and diameter is 3.68 nm as demonstrated by XRD. The morphology of nanocrystals is spherical measured by TEM which shows the similar particle size. The photoluminescence spectrum peaking at about 424 nm was due mostly to the trap-state emission, and a satellite peak at 480nm ascribed to the dangling bond of S in the surface of ZnS nanocrystals. The emission intensity of ZnS was enhanced after ultraviolet irradiation, the enhancement of the Photoluminescence intensity was due to the elimination of the surface defects after ultraviolet irradiation, for the growth of the coated shell on ZnS nonacrystals, the Photoluminescence intensity was increased as ultraviolet irradiation time growth, finally tends to be stable for the surface state of nanocrystals steady.

• Periodical: Applied Mechanics and Materials (Volumes 556-562)
• Pages: 27-31
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.556-562.27
• Online since: May 2014
• Authors: Ling Ling Peng, Bi Tao Liu*, Tao Han
• Keywords: Fluorescence Enhancement, Nanocrystal, Photoluminescence (PL)

References

[1] V. Nikesh , A. Dharmadhikari, H. Ono, S. Nozaki, G. Kumar, S. Mahamuni: Appl Phys Lett Vol. 84（2009）, pp.4602-4604.

DOI: 10.1063/1.1748840

[2] V. V. Bakhmetyev, K. A. Ogurtsov, M. M. Sychov, A. A. Kotomin, S. A. Dushenok, A. S. Kozlov, G. Xu: Inorg Mater Vol 48 (2012)no 9, p.884.

DOI: 10.1134/s0020168512090038

[3] X.H. Gao, W. C. W. Chan, S. Nie, J. Biomed: Opt Vol 7 (2002), pp.532-537.

[4] A.L. Rogach, N. Gaponik, J.M. Lupton: Angewandte Chemie International Edition Vol 47(2008), no 35, p.6538–6549.

[5] Q.Q. Dai, C. E. Duty, M.Z. Hu: small Vol. 6(2010), pp.1577-1588.

[6] X. Fang, Y. Bando, M. Liao, U.K. Gautam, C.Y. Zhi, B. Dierre, B. D. Liu, T.Y. Zhai, T. Sekiguchi, Y. Koide, D. Golberg: Advanced Materials Vol. 21(2009), p.2034-(2039).

DOI: 10.1002/adma.200802441

[7] Y. Yang, M.Y. Gao: Adv. Mater Vol. 17(2005), p.2354–2357.

[8] L. Chun, M. Norio: Langmuir , vol. 20(2004), p.1–4.

[9] H. Yang, P.H. Holloway, B.B. Ratna: J. Appl. Phys Vol. 93(2003), pp.586-592.

[10] J. F. Suyver, S.F. Wuister, J. J. Kelly, A. Meijerink: Nano Lett Vol 1(2001), p.429–433.

[11] H.Y. Lu, S.Y. Chu, S .S. Tan:J. Crys Growth Vol. 269, (2004) pp.385-391.

[12] W. G. Becker, A. J. Bard, J. Phys. Chem Vol. 87(1983), pp.4888-4893.