The Research Of Coupling Between Plasmon Mode And Photothermal Properties Of Metal Nanoparticles

Metal nanoparticles shows great prospects in the field of photonic devices, biochemistry sensing, biological markers, etc., because of its unique properties localized surface plasmon resonance(Local surface plasmon resonance, LSPR) when it interact with the light in the past 20 years. The resonance absorb of metal nanoparticles dominant the important role when the diameter of metal nanoparticles less than 50 nm, thus produce heat, therefore the metal nanoparticles can be used as efficient, localized and can be controlled by laser nanometer source to achieve thermal control on the nanometer scale. This make the photothermal properties of metal nanoparticles have increasingly become a hot academic research in the recent years. Although the thermal effects of plasmonic particles have been widely used in biomedical treatment, solar thermal imaging and other fields, which the physical mechanisms of produce heat and heat transfer are still have many questions to be answered, Especially the effect of surface plasmon resonance to the temperature change is unclear. At present most research about the photothermal properties of single metal nanoparticles are studying the effects of surrounding medium, the size of the nanoparticles as well as the shape to the resonance wavelength. However, there are many studies about what the optical properties of the metal nanoparticle arrays, but most studies only consider the role of dipole mode,higher order modes rarely been studied, and sometimes even directly ignored.To solve the above problems, this paper study the surface plasma resonance peak which produced by single metal nanoparticles of Different shape, and the coupling resonance of bimetallic arrays associated with temperature changes, respectively. We first quantitative study of localized surface plasmon resonance effect and thermal coupling phenomenon of the individual metal nanoparticles by use finite element multi-physics simulation software COMSOL Multiphysics, and qualitative analysis of the physical cause of various plasma resonance peak and the temperature generated. We found that when the cross-sectional area equal to various metal nanoparticles, the sharper the particle, the higher the temperature of the particles, the more resonance peaks of plasma mode, The larger the resonance wavelength red shift in the same conditions. Nextly we studies the nteraction of two different materials Au and Ag in same shape to the plasmon mode and temperature. It was found that the resonance wavelength red shift, the number of resonance peaks increases, the higher the temperature of the particles when the distance between the particles is reduced; We also found that the impact of distance to the Au nanospheres is greater than Ag nanoparticles. Our results can provide theoretical guidance for the product nano-rule, which based on the temperature of different materials used to measure length. This provides the basis for us to more flexible select the shape of nanostructures and resonance peak in the future.