Tunable surface plasmon resonance frequencies of monodisperse indium tin oxide nanoparticles by controlling composition, size, and morphology.

Keke Ma,Meng Yuan,Deren Yang,Ning Zhou,Dongsheng Li

doi:10.1186/1556-276x-9-547

Abstract

Monodisperse indium tin oxide nanoparticles (ITO NPs) with high crystallinity have been synthesized by the rapid thermal injection method and the seed-mediated growth method. We demonstrate that the surface plasmon resonance (SPR) frequencies of ITO NPs can be manipulated from 1,600 to 1,993 nm in near-infrared band by controlling the composition, size, and morphology. The doping Sn concentration in ITO NPs could be controlled via changing the %Sn in the initial feed from 0% to 30%. The shortest SPR wavelength at 1,600 nm with 10% Sn doping concentration indicates highest free electron carrier concentration in ITO NPs, which has direct relationship with doping Sn4+ ions. Furthermore, we demonstrate that the SPR peaks can also be tuned by the size of ITO NPs in the case of uniform doping. Besides, compared with the ITO NPs, single crystalline ITO with nanoflower morphology synthesized through the one-pot method exhibit SPR absorption peak features of red-shifting and broadening.

Highlights

The research in the field of plasmonics has spurred a tremendous amount of interest and found a wide variety of applications, including chemical and biological sensing, fluorescence, waveguide, and novel optical devices [1,2,3,4,5]
Crystal structure and composition of ITO Indium tin oxide nanoparticles (NPs) indium tin oxide nanoparticles (ITO NPs) with different Sn doping concentration were synthesized through changing the concentration of tin precursors in the reagents by the hot-injection approach
The most notable feature of these ITO samples is that the morphology of ITO NPs tends to be more irregular, and the size becomes somewhat smaller when increasing the Sn doping concentration

Summary

Introduction

The research in the field of plasmonics has spurred a tremendous amount of interest and found a wide variety of applications, including chemical and biological sensing, fluorescence, waveguide, and novel optical devices [1,2,3,4,5]. The conventional plasmonic materials such as gold and silver suffer from high-losses caused by interband transition at optical frequency range. Another drawback of noble metals is that their optical properties cannot be adjusted as the carrier density cannot be tuned arbitrarily. The challenge of compatibility with CMOS technology is mainly caused by diffusion problems between silicon and noble metals which seriously affect the performance of the plasmonic and metamaterial devices [6,7].

Methods

Results

Conclusion