Selective and Tunable Near‐Infrared and Visible Light Transmittance of MoO_3−x Nanocomposites with Different Crystallinity

Abstract

In this Communication, we report MoO nanocomposites in which the near-infrared and visible light transmittance can be selectively modulated through the crystallinity. The MoO nanocomposites were fabricated by a hydrothermal method, and their optical properties were characterized by UV-Vis spectrometer. The obtained results proved the possibility to tune the nanocomposite's optical properties in the UV/Visible spectral region: crystalline MoO mainly regulates the near-infrared range (800-2600 nm), and amorphous MoO mainly changes the visible range from 350 nm to 800 nm and MoO , with semi-crystalline structures mainly modulating around 800-1000 nm. These kinds of optical modulations could be attributed to small polar absorption, free electron absorption and plasmon absorption according to different crystallinity. Our work may create new possibilities for future applications such as photochromism, photocatalysis, and electrochromism.

Amorphous Materials for Enhanced Localized Surface Plasmon Resonances

“… Transmittance of a) S1, b) S2, and c) S3 under the same concentration. Reprinted from reference . Copyright 2017 Wiley‐VCH.…”

“…It is thus speculated that the effect of crystallinity on their LSPR properties might be significant, as selective tunable solar light is very important for many applications. An example is the work by Li et al . Their study indicated that the different crystallinity of MoO 3− x nanocomposites can have an effect on oxygen deficiencies as well as the plasmon resonance shape and position.…”

Review on thermochromic vanadium dioxide based smart coatings: from lab to commercial application

“…Most work on VO 2 based smart coatings pursue large contrast of optical transmittance in the near infrared region (780-2 500 nm), while inconspicuous contrast in the visible light region (380-780 nm) is desirable for both semiconducting and metallic states. In the solar spectrum, ultraviolet light, visible light and infrared light is responsible for about 7%, 50%, 43% of solar energy, respectively [23]. Therefore, if there is an increased contrast in the visible light region for VO 2 based smart coatings between the semiconducting and the metallic state, relative solar Review on thermochromic vanadium dioxide based smart coatings… 7 modulation ability can be robustly enhanced due to the contribution from the visible light region.…”

“…Therefore, smart coatings based on electrochromism [6][7][8][9][10], thermochromism [11][12][13][14][15][16][17][18][19], gasochromism [20][21][22] and photochromism [23][24][25][26] have been widely studied for energy efficient coatings. Thermochromic smart coatings can modulate near-infrared radiation from transmissive to opaque in response to the environmental temperature from low to high, which does not require extra stimuli and can save more energy consumption.…”

“…(ii) For conventional VO 2 coatings, relative modulation abilities are not efficient enough for energy saving. That can be explained by the fact that the modulation of VO 2 for solar radiation is most attributed to the transmittance switch in the near-infrared region, which only accounts for 43% of solar energy in the solar spectrum [23]. (iii) The luminous transmittance T lum for single layer VO 2 with desirable (DT sol ) is usually less than 40% (even 30%) due to the absorption in the short-wavelength range in both the semiconducting and metallic states of VO 2 , which should be larger than 50% at least for daily applications.…”