Impact of Zn and W Doping Levels on Properties of Thermochromic VO2-Based Thin Films

Haji F. Haji, Department of Natural Sciences, The State University of Zanzibar, P.O. Box 146, Zanzibar, TanzaniaFollow
Margaret E. Samiji, Department of Physics, University of Dar es Salaam, P.O. Box 35063, Dar es Salaam, TanzaniaFollow
Nuru R. Mlyuka, Department of Physics, University of Dar es Salaam, P.O. Box 35063, Dar es Salaam, TanzaniaFollow

Section

Physical Sciences

Abstract

DC magnetron sputtering at a substrate temperature of 425 °C was used to successfully deposit W/Zn-doped VO2 thin films on soda lime glass (SLG) substrates. The aim was to investigate the influence of Zn doping levels on the transition temperature ( ), luminous transmittance (Tlum) and solar transmittance modulation (ΔTsol) of VO2-based thin films. UV/VIS/NIR spectrometer, X-ray Diffraction (XRD), Atomic Force Microscope (AFM), and Rutherford Backscattering Spectroscopy (RBS) were used to characterise the thin films. It was revealed that W/Zn co-doped VO2 thin films with ~ 10.8 at.% Zn showed a luminous transmittance of ~ 40.4%, with excellent solar transmittance modulation of 10.2%. Furthermore, the transition temperature obtained for the Zn and W co-doped VO2 films with ~ 10.8 at.% Zn was lower at 23.1 °C compared to 25.6 °C and 26.8 °C for thin films with ~ 3.9 at.% Zn and ~ 2.8 at.% Zn, respectively. It was not possible to deposit the films with Zn doping level above 10.8 at.% due to some technical limitations. These findings indicate that thin films with a controlled proportion of Zn in the W/Zn co-doped VO2-based thin films have the potential to be employed for applications such as smart windows.

Recommended Citation

Haji, Haji F.; Samiji, Margaret E.; and Mlyuka, Nuru R. (2023) "Impact of Zn and W Doping Levels on Properties of Thermochromic VO2-Based Thin Films," Tanzania Journal of Science: Vol. 49: Iss. 4, Article 3.
Available at:https://doi.org/10.4314/tjs.v49i4.3