Semiconductor nanocrystals are promising materials for light emitting devices and biological imaging probes because of their high fluorescent quantum yield. However, multiphoton emission efficiency of single semiconductor nanocrystals is often low, due to fast non-radiative recombination of multiexcitons. Multiexciton emission of single semiconductor nanocrystals can be enhanced when they located in close proximity to gold nanoparticles. When excited by light, gold nanoparticles can concentrate light in a small volume next to the gold nanoparticles, due to the excitation of localized surface plasmon.  The enhanced field can increase the excitation rate of the semiconductor nanocrystals. Meanwhile, the radiative and non-radiative rates of multiexciton are both increased according to electrodynamics simulation, leading to enhanced multiexciton emission intensity. Moreover, we find the extent of the enhancement of multiexciton emission intensity is dependent on the wavelength of the excitation source. This dependence is mainly resulted from wavelength-dependent excitation rate of multiexcitons in semiconductor nanocrystals near gold nanoparticles. The research shows that exciton-plasmon interaction in semiconductor-metal nanostructures can be easily modulated by the excitation wavelength.<br/>

Excitation wavelength dependent multiphoton emission of single semiconductor nanocrystal near gold nanoparticles

254th National Meeting (2017)

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