High quality VO2 thin films synthesized from V2O5 powder for sensitive near-infrared detection

Abstract

Vapor transport method has been successfully used to synthesize high quality VO2 thin films on SiO2/Si substrate using V2O5 as a precursor in an inert-gas environment. The morphological and structural evolutions of the intermediate phases during the nucleation and growth processes were investigated by SEM and Raman spectroscopy, respectively. The results showed that the conversion of V2O5 powder to VO2 thin films was dominated by a melting-evaporation-nucleation-growth mechanism. Further characterization results demonstrated that the high quality crystals of monoclinic VO2 thin films exhibit a sharp resistance change up to 4 orders of magnitude. In addition, the VO2 thin films exhibited good near-infrared response, high stability, and reproducibility under ambient conditions, which should be promising for sensitive near-infrared detection. Our work not only provided a simple and direct approach to synthesize high quality VO2 thin films with distinct phase transition properties but also demonstrated the possible infrared sensing application in the future.

Facile Synthesis of Two Dimensional (2D) V2O5 Nanosheets Film towards Photodetectors

“…Furthermore, the peaks at 405 and 284 cm −1 are bending vibration of the V=O (terminal oxygen) bonds, and the peaks at 304 and 481 cm −1 are bending vibrations of V 3 -O (triply coordinated oxygen) bonds and V-O-V (bridging doubly coordinated oxygen), respectively. Moreover, the peak in 700 cm −1 belongs to the asymmetric stretching of V 2 -O (doubly coordinated oxygen) bonds, and the intensity feature at 993 cm −1 belongs to the stretching vibrations of V=O (terminal oxygen) vanadyl bonds in V 2 O 5 , which is distinguished from other vanadium oxide in the Raman spectrum [ 32 , 59 , 60 ].…”

Effect of microplate size on the semiconductor–metal transition in VO2 thin films

“…More importantly, based on the observed processes, we found that using a larger amount of precursor causes large nuclei to form on the oxide substrate during the initial growth stage, and this advantage is maintained during subsequent growth stages, resulting in the formation of larger microplates in the complete VO 2 thin film. 20…”

“…11,12 Furthermore, the phase transition is accompanied by rapid and ultrafast variations in resistivity and optical transmittance, particularly in the infrared range. 13–16 These excellent features of VO 2 make it a promising candidate for many practical applications, such as sensors, 17 memory devices, 18 photodetectors, 19,20 smart windows, 13 and ultrafast optical switches. 14…”

Tunable directional filter for mid-infrared optical transmission switching

“…The multilayer structure can be feasibly fabricated using thin film deposition techniques. Growth of VO2 thin films on the order of 100nm thick have been demonstrated using RF magnetron sputtering [25] and thicker high quality VO2 films have recently been demonstrated using the vapor transport method [26]. Likewise, CaF2 films of micron thickness have been deposited using resistive evaporation [27].…”