Influence of film thickness on structural and optical-switching properties of vanadium pentoxide films

Abstract

Vanadium oxide films were deposited at different sputtering times on sapphire substrates by radio frequency reactive magnetron sputtering. The effects of thickness on the surface structural, morphology and optical-switching properties of the films were studied comprehensively. X-ray diffraction results show that all the prepared films are polycrystalline vanadium pentoxide films (V 2 O 5 ) on (001) preferred orientation. Both root-mean-square roughness and average surface grain size decrease with the increase of thickness. With the thickness reduction, the closing time decreases first and then increases at the turning point of 350 nm, and the maximum and the minimum are 2.7 ms at 600 nm and 1.7 ms at 350 nm, respectively. The recovery time decreases rapidly with the reduction of the film, which varies from 40 ms at 600 nm to 27 ms at 150 nm. More concerning, the dynamic range of transmittance varies greatly from thickness, and the transmittance ratio before and after the phase transition covers from 3.75 at 150 nm to the maximum of 7.3 at 600 nm under a continuous probe light of 1064 nm.

Comparison of vanadium oxide thin films deposited from commercial and solution combustion synthesised powders

“…During the coating, the thickness of the film was not stable because of the spin force (centrifugal force), and it was found in a relatively wide range (100–300 nm). The main reason for this was the increase of the centrifugal force toward the edge of the film from the centre [20]. Owing to this difference, the central region of the film had a relatively larger thickness when compared with the edges.…”

“…In the past, vanadium oxide thin films have generally been produced by different methods such as sputtering [19,20], pulsed laser deposition [21], electron beam evaporation [22], spray pyrolysis [13] and sol–gel [11,23], etc. However, deposition of thin films by the sol–gel method stood out from the rest and has drawn more attention than the other techniques due to its low cost, easy procedure, lower operation temperature and ability to control of stoichiometry [11,23].…”

Microstructure and Performance of a Porous Polymer Membrane with a Copper Nano-Layer Using Vapor-Induced Phase Separation Combined with Magnetron Sputtering

“…However the mean particle diameter of the membrane surface increased with further sputtering ( Figure 1 d,e and Table 1 ). The film formation mechanism has a direct influence on the film structure and optical-switching properties [ 21 ]. It is essential to understand the mechanism of film growth, which consists of particle–particle and particle–substrate interactions [ 22 ].…”

Temperature effect on structural and optical properties of V2O5 thin films prepared by spray pyrolysis technique

“…Because of their permanent structural flexibility associated with their chemical and physical properties. Different oxidation states can be obtained depending on the method of preparation and the type of source material, such as VO2, V2O3 and V2O5… [3,4].Vanadium pentoxide (V2O5) is the most oxidized state, the most stable form of crystallizationand most applicable in industry, mainly in Li-ion batteries [5,6], electrochromic and thermoelectric devices [7,8], gas sensors [9,10] and opto-electronic switches [11,12].…”