Tungsten Oxide Plasma Resonance Effect

Plasma resonance is a physical optical phenomenon. It utilizes the disappearance of light penetrating into the tungsten oxide film when total internal reflection occurs at the interface between the glass and the tungsten oxide film, causing free electrons in the tungsten oxide to generate surface plasma. In the past few decades, the local surface plasmon resonance effect has been simply considered as the optical properties of noble metal nanoparticles. However, with the discovery of LSPR in semiconductor and oxide nanocrystals, this view is changing. The plasma resonance effect on semiconductors and tungsten oxide materials is mostly achieved by doping noble metals.

Three kinds of tungsten oxide near infrared test. In the wavelength range of 350-1400 nm, the bulk tungsten oxide has no obvious absorption peak in the visible and near infrared regions. The W-300 and W-400 samples all have obvious absorption peaks around 1050 nm in the near infrared region. It was shown that the two samples after hydrogenation exhibit surface plasmon resonance effects.

A simple hydrogenation makes tungsten oxide exhibit a plasmon resonance effect. This is because of the introduction of oxygen vacancies into the tungsten oxide and the formation of an oxygen-deficient structure of tungsten oxide. The presence of oxygen vacancies makes free carrier density more than 1021 cm, causing collective turbulence of surface free carriers to induce surface plasmon resonance. Comparing the W-300 and W-400 samples, we found that the W-300 sample exhibited a more pronounced plasmon resonance effect. This may be due to the better crystallinity of the W-300 sample except for the edge region after introduction of oxygen vacancies, whereas the W-400 sample has a larger disordered area and poor crystallinity, lowering the plasma resonance intensity. From the principle of plasmon resonance, the dark blue W-400 sample absorbs less photon energy when reflected light is irradiated. Excited free carrier density relative to the W-300 sample less, so the performance of the weak plasma resonance effect.

• < Prev
• Next >