Infrared Solar Thermal-Shielding Applications Based on Oxide Semiconductor Plasmonics

Abstract

This chapter describes plasmonic responses in In 2 O 3 :Sn nanoparticles (ITO NPs) and their assembled ITO NP sheets in the infrared (IR) range. ITO NPs clearly provide resonance peaks related to local surface plasmon resonances (LSPRs) in the near-IR range, which are dependent on electron density in the NPs. In particular, electron-impurity scattering plays an important role in determining carrier-dependent plasmon damping, which is needed for the design of plasmonic materials based on ITO. ITO NPs are mainly dominated by light absorption. However, a high light reflection is observed in the nearand mid-IR range when using assembled NP sheets. This phenomenon is due to the fact that the introduction of surface modifications to the NPs can facilitate the production of electric-field (E-field) coupling between the NPs. The three-dimensional (3D) E-field coupling allows for resonant splitting of plasmon excitations to the quadrupole and dipole modes, thereby obtaining selective high reflections in the IR range. The high reflective performances from the assembled NP sheets were attributed to the plasmon interactions at the internanoparticle gaps. This work provides important insights for harnessing IR optical responses based on plasmonic technology toward the fabrications of IR solar thermal-shielding applications.

PMMA-ITO Composite Formation via Electrostatic Assembly Method for Infra-Red Filtering

“…Three-dimensional (3D) field interactions along the in-plane and out-plane direction would then provide high light reflections in the near- and mid-IR regions [11]. The 3D electric field coupling phenomenon would generate resonant splitting of plasmon excitations to the quadrupole and dipole modes and therefore, obtaining selective high reflections in the IR range [22]. As the control of the inter-particle distance still remains a challenge, our novel method of electrostatic assembly allows good ITO nanoparticles distribution on PMMA, which exhibit better controllability in the adjustment of ITO nanoparticles inter-particle gap.…”

“…By controlling the amount of ITO nanoparticle distribution within the PMMA matrix in a homogenous fashion using electrostatic assembly, the control of inter-particle gap of ITO nanoparticles is feasible. Subsequently, the near 3D distribution of ITO nanoparticles in the matrix would allow the generation of electric field coupling and resonant splitting of plasmon excitations for IR rays reflectance [11,22]. In comparison with the work reported by Arlindo et al, they incorporated ITO nanowires into PMMA and the optical transmittance reduced linearly with the amount of ITO addition [3].…”