Chemical structures and physical properties of vanadium oxide films modified by single-walled carbon nanotubes

Abstract

A series of vanadium oxide (VOx)-single-walled carbon nanotube (SWCNT) composite films with different SWCNT concentrations were prepared and systematically investigated. The results reveal that after SWCNT addition, the optical absorption and electrical conductivity of VOx are enhanced, but the crystallinity and temperature coefficient of resistance (TCR) are weakened. Consequently, either too low or too high CNT loading will lead to the degradation of the comprehensive properties. In contrast, the VOx-SWCNT composite film containing 4 wt% SWCNTs exhibits the optimal comprehensive properties such as high film uniformity, large optical absorption, and desirable sheet resistance (141 kΩ) and TCR (-1.73% K(-1)), favorable for applications in uncooled infrared detectors. Saturated interactions between SWCNTs and VOx are observed at 6 wt% SWCNTs, after which (≤10 wt% SWCNTs) the structures and properties are changed slightly. This work reveals the modification of the chemical structures and physical properties of VOx films by SWCNTs, whose results will be helpful not only for a better understanding of VOx, SWCNTs, and their composites, but also for seeking new versatile functional materials for device applications.

Comparison on modifications of vanadium oxide thin films by single-walled and multi-walled carbon nanotubes

“…SEM images (Fig. 1) suggest that both MWCNTs and SWCNTs are chemically interacted with VO x , thus modifying the morphology and crystallinity of VO x [3]. Moreover, the interactions between VO x and MWCNTs seem stronger than those between VO x and SWCNTs.…”

“…With the rapid development of devices, further improvements on the chemical structures and physical properties of such materials are required. One of the most efficient ways to adjust the properties of VO x is preparing composite materials, among which VO x -CNT composites have drawn considerable attentions [2,3].…”

Carbon nanotube versus graphene in modifying the electrical and optical properties of organic nonlinear optical material

“…It is known that carbon nanotube (CNT) and graphene (G) are two of the most important and widelyapplied nanomaterials for enhancing the electrical properties of organic and inorganic materials (Geim and Novoselov 2007;Bai et al 2011;Wang et al 2015a). In fact, the optical properties can also be modified by CNT or G, owing to their unique optical properties and inherent geometric structures (He et al 2015;Chen et al 2018).…”

“…Up to now, many literatures about modifications of the electrical and/or optical properties of organic or inorganic materials by CNT or G have been previously reported (He et al 2015;Chen et al 2018;Li et al 2011;Zhang et al 2010). For example, He and co-workers reported that both the electrical conductivity and infrared absorption of VO x film can be efficiently enhanced by CNTs (He et al 2015).…”

“…Up to now, many literatures about modifications of the electrical and/or optical properties of organic or inorganic materials by CNT or G have been previously reported (He et al 2015;Chen et al 2018;Li et al 2011;Zhang et al 2010). For example, He and co-workers reported that both the electrical conductivity and infrared absorption of VO x film can be efficiently enhanced by CNTs (He et al 2015). Similarly, Li et al claimed that the electrical resistance of organic poly(methyl methacrylate) film is significantly reduced by eight orders of magnitude after addition of vertically-aligned CNTs to the polymer (Li et al 2011).…”