Hybrid dimer composed of silicon nanospheres of different sizes for fluorescence enhancement

Abstract

Abstract: Micro-nano structure with unique optical properties are commonly used in micro-nano optics to achieve luminescence enhancement of fluorescent substance. In order to improve the luminous efficiency of quantum dots (QDs), a dimer structure composed of two silicon nanospheres of different sizes is proposed. By utilising the finite-difference time-domain (FDTD) method, the enhancement in the quantum yield and fluorescence excitation rate are investigated to illustrate the fluorescence enhancement effect of the silicon nanospheres dimer. Results show that the luminous intensity of CdSe QDs can be greatly enhanced by dimers composed of two silicon nanospheres of different sizes. When the two silicon nanospheres have smaller diameter and smaller gap, the quantum yield and fluorescence excitation rate of the QDs can be enhanced more. In particular, when the diameter of the two silicon nanospheres is 100 nm and the gap is 10 nm, the fluorescence intensity of the CdSe quantum dot can be enhanced by approximately a factor of 209. The research results are of certain guiding significance for the design and development of high-performance quantum dot photoluminescence devices.

Key words: micro-nano optics, silicon dimer, finite difference time domain method, quantum dot, fluorescence enhancement

MI Zhi1,2, LI Ning1,2*. Hybrid dimer composed of silicon nanospheres of different sizes for fluorescence enhancement[J]. Chinese Journal of Quantum Electronics.

References

[1] Peng Huiren, Jiang Yibin, Chen Shuming. Efficient vacuum-free-processed quantum dot light-emitting diodes with printable liquid metal cathodes [J]. Nanoscale, 2016, 8(41): 17765-17773. [2] van Driel A F, Allan G, Delerue C, et al. Frequency-dependent spontaneous emission rate from CdSe and CdTe nanocrystals: Influence of dark states [J]. Physical Review Letters, 2005, 95(23): 236804. [3] Li Qile, Ding Shounian. Multicolor electrochemiluminescence of core-shell CdSe@ZnS quantum dots based on the size effect [J]. Science China Chemistry, 2016, 59(11): 1508-1512. [4] Liang Litao, Xie Wenfang. Influence of the shape of quantum dots on their optical absorptions [J]. Physica B: Condensed Matter, 2015, 462: 15-17. [5] Schuller Jon A, Barnard Edward S, Cai Wenshan, et al. Plasmonics for extreme light concentration and manipulation [J]. Nature Materials, 2010, 9(3): 193-204. [6] Noginov M A, Zhu G, Belgrave A M, et al. Demonstration of a spaser-based nanolaser [J]. Nature, 2009, 460(7259): 1110-1112. [7] Lakowicz J R, Shen Yibing, D'Auria Sabato, et al. Radiative decay engineering. 2. Effects of Silver Island films on fluorescence intensity, lifetimes, and resonance energy transfer [J]. Analytical Biochemistry, 2002, 301(2): 261-277. [8] Qiu Dong, Wang Yong, Zhu Liangf, et al. Fluorescence enhancement and directional radiation based on hybrid aperture-Tamm structure [J]. Chinese Journal of Quantum Electronics (量子电子学报), 2018, 35(1): 1-6 (in Chinese). [9] Zhang Zhenyu, Wang Haiyu, Du Jianglin, et al. Surface plasmon-modulated fluorescence on 2D metallic silver gratings [J]. IEEE Photonics Technology Letters, 2015, 27(8): 821-823. [10] Mai Weijie, Song Xiaokang, Jiang Ping, et al. Control of the two-photon fluorescence of quantum dots coupled to silver nanowires [J]. Optics Express, 2016, 24(24): 27870-27881. [11] Liu Gang L, Kim Jaeyoun, Lu Yu, et al. Fluorescence enhancement of quantum dots enclosed in Au nanopockets with subwavelength aperture [J]. Applied Physics Letters, 2006, 89(24): 241118. [12] Peng Bo, Li Zhenpeng, Mutlugun Evren, et al. Quantum dots on vertically aligned gold nanorod monolayer: Plasmon enhanced fluorescence [J]. Nanoscale, 2014, 6(11): 5592-5598. [13] Shan Feng, Su Dan, Li Wei, et al. Hot spots based gold nanostar@SiO2@CdSe/ZnS quantum dots complex with strong fluorescence enhancement [J]. AIP Advances, 2018, 8(2): 025219. [14] Regmi R, Berthelot J, Winkler P M, et al. All-dielectric silicon nanogap antennas to enhance the fluorescence of single molecules [J]. Nano Letters, 2016, 16(8): 5143-5151. [15] Anger P, Bharadwaj P, Novotny L. Enhancement and quenching of single-molecule fluorescence [J]. Physical Review Letters, 2006, 96(11): 113002. [16] Sun S, Wu L, Bai P, et al. Fluorescence enhancement in visible light: Dielectric or noble metal? [J]. Physical Chemistry Chemical Physics, 2016, 18(28): 19324-19335. [17] Albella P, Ameen P M, Schmidt M K, et al. Low-loss electric and magnetic field-enhanced spectroscopy with subwavelength silicon dimers [J]. Journal of Physical Chemistry C, 2013, 117(26): 13573-13584. [18] Rutckaia V, Heyroth F, Novikov A, et al. Quantum dot emission driven by Mie resonances in silicon nanostructures [J]. Nano Letters, 2017, 17(11): 6886-6892. [19] Zhang Wenjun, Zhai Baocai, Xu Jian. Fabrication and characterization of green CdSe quantumn dot light emitting diodes with ZnO electron-transport layer [J]. Chinese Journal of Luminescence (发光学报), 2012, 33(11): 1171-1176 (in Chinese). [20] Devilez A, Stout B, Bonod N. Compact metallo-dielectric optical antenna for ultra directional and enhanced radiative emission [J]. ACS Nano, 2010, 4(6): 3390-3396. [21] Das G M, Ringne A B, Dantham V R, et al. Numerical investigations on photonic nanojet mediated surface enhanced Raman scattering and fluorescence techniques [J]. Optics Express, 2017, 25(17): 19822-19831. [22] Palik E D. Handbook of optical constants of solids[M]. Academic Press,1998.