Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (10): 1827-1836.doi: 10.3866/PKU.WHXB201408011

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Surface Plasmon Resonance Coupling Effect of Assembled Gold Nanorods Based on the FDTD Simulation

LI Yu-Ling1, KAN Cai-Xia1,2, WANG Chang-Shun1, LIU Jin-Sheng1, XU Hai-Ying1, NI Yuan1, XU Wei1, KE Jun-Hua1, SHI Da-Ning1,2   

  1. 1. Department of Applied Physics, College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, P. R. China;
    2. Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, P. R. China
  • Received:2014-05-27 Revised:2014-08-01 Published:2014-09-30
  • Contact: KAN Cai-Xia, SHI Da-Ning E-mail:cxkan@nuaa.edu.cn;shi@nuaa.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (11274173, 51032002, 61222403, 11374159).

Abstract:

Much attention has been given to the optical properties of noble metal nanostructures and these are closely related to the size, morphology, and environment of the nanoparticles. In this paper, the influences of structures and assembly modes on the surface plasmon resonance (SPR) of Au nanorods were studied through a finite-difference time-domain (FDTD) simulation on Au nanorod assemblies (dimers and multimers) of different configurations. The simulated optical spectra agree well with the experimental results. The simulated results for the side-by-side (S-S) oriented Au nanorods indicate that the transverse SPR (SPRT) has a slight redshift, and the longitudinal SPR (SPRL) blue-shifts obviously. For the end-to-end (E-E) oriented Au nanorod dimer, the results indicate that with a decrease in the gap spacing of the E-E oriented Au nanorods, the SPRT does not shift while the SPRL red-shifts obviously. Moreover, a new coupling SPR peak appears in the near-infrared (NIR) region, blue-shifting and enhancing with a decrease in the gap spacing. Based on the spring oscillator model and the polarization of the nanoparticles under an incident electric field, we propose a reason for the SPR shift and the appearance of a new coupling SPR for the Au nanorod assemblies.

Key words: Gold nanorod, Assembly, Finite-difference time-domain method, Surface plasma resonance, Coupling effect

MSC2000: 

  • O642