Photothermal Effect and Phase Transition in VO2 Enhanced by Plasmonic Particles

Abstract

Phase change metasurfaces based on VO2, which are pre-heated with electric current and optically addressed by projected structured light hologram, are considered to become a new paradigm in programmed THz/middle IR flat optics. Macroscopic quasi-homogeneous arrays of Au nanoparticles show large near IR absorption and a significant photothermal effect capable of boosting a light-triggered switching of VO2 and are to be carefully examined. We propose a new approach to simultaneously probe the altered temperature and electric conductivity of a hybrid Au particle-VO2 film composite by monitoring a phase shift and attenuating a surface acoustic wave in a YX128° cut LiNbO3 substrate. The method shows a temperature resolution of 0.1 °C comparable with the best existing techniques for studying nanoobjects and surfaces. The laser-induced photothermal effects were characterized in a macroscopic array of Au nanostars (AuNSts) with different surface coverage. In a monolayer of 10 nm Au, coupled plasmonic nanoparticles were deposited on the LiNbO3 substrate. An optically triggered insulator-metal transition assisted by photothermal effect in AuNSts/VO2/TiO2/LiNbO3 composites was studied at varied light power. We believe that the proposed SAW-based method is of significant importance for the characterization and optimization of radiation absorbing or/and electrically heated elements of metasurfaces and other devices for lab-on-chip and optical communication/processor technology.

Temperature-Controlled and Adjustable Terahertz Device Based on Vanadium Dioxide

“…Among them, a MDD cannot form an effective resonant cavity, so that the terahertz wave incident on the surface is almost completely reflected, achieving the effect of high reflection. MDM is a classical resonant cavity, which can resonate the electromagnetic wave at a specific frequency and produce high absorption [49,50]. In fact, the surface plasmon resonance (SPR) caused by the matching of the frequency of the device structure and the frequency of terahertz wave is the reason for the high absorptivity of the device.…”

Low-Dimensional Structures for Smart Materials and Composites: Preparation, Properties and Applications

“…In conclusion, a moderate magnetic field of 0.1 T induced significant effects on the magnetic anisotropy, suggesting a magneto-strictive influence rather than direct effects on growth kinetics, which can be adopted for tailoring magnetic of more complex epitaxial heterostructures. Kaydashev et al [22] presented a method involving the exploitation of surface acoustic waves (SAWs) to simultaneously probe the altered temperature and electrical conductivity of a hybrid Au nanoparticles-VO 2 film composite heated and exposed by laser light. The authors reported a resolution of ±0.1 • C, which is comparable with the best existing techniques to study small objects and surfaces.…”