Structural and optical properties of vanadium pentoxide nano-thin films with different thickness

ABSTRACT

Vanadium pentoxide nano-thin films were deposited on JGS infrared quartz substrates by radio frequency (R.F.) reactive magnetron sputtering at different sputtering times. The effects of thickness on the surface structural and optical properties of the films were studied systematically. X-ray diffraction (XRD) results show that all the prepared nano-films are polycrystalline vanadium pentoxide films (V₂O₅) on (001) preferred orientation. The Root-Mean-Square (RMS) roughness decreases from 2.8 nm to 1.2 nm with the increase of thickness. Optical properties were measured by an optical-testing setup. The results indicate that both the optical turn-off time and turn-on time diminish with the reduction of the film thickness, which cover from 2.1 ms and 39 ms at 447 nm to the minimum of 1.5 ms and 27 ms at 154 nm respectively. Additionally, the dynamic range of transmittance varies greatly from 3.16 at 154 nm to the maximum of 5.89 at 447 nm under a laser beam of 1064 nm.

KEYWORDS:

• V₂O₅ nano-films
• thickness
• surface morphology
• optical properties

Funding

This study is supported by National Natural Science Foundation of China (Grant No.51275230), Aeronautical Science Foundation of China (Grant No.20140152001), Funding of Jiangsu Innovation Program for Graduate Education (No.KYLX_0226) and the Fundamental Research Funds for the Central Universities.