Temperature dependence of the surface plasmon resonance in gold nanoparticles

The temperature dependences of energy and width of the surface plasmon resonance were studied for gold nanoparticles with sizes 20–55 nm in silica host matrix in the temperature range 17–915 °С. The increase of temperature leads to appreciable red shift and broadening of the surface plasmon resonance in Au nanoparticles. The obtained dependences were analyzed within the framework of theoretical model considering the thermal expansion of the nanoparticle, the electron–phonon scattering in the nanoparticle and the temperature dependence of dielectric permittivity of the host matrix. The thermal expansion was shown to be the main mechanism responsible for the temperature induced red shift of the surface plasmon resonance in gold nanoparticles. The thermal volume expansion coefficient for Au nanoparticles was found to be size-independent in the studied size range. Meanwhile, the increase of electron–phonon scattering rate with increasing temperature was shown to be the dominant mechanism of the surface plasmon resonance broadening in the gold nanoparticles.