Sol–gel synthesized ZnO thin films doped with Rb and Al for self-cleaning antibacterial applications

Aluminum and rubidium-doped zinc oxide thin films were deposited utilizing sol–gel dip coating on glass substrates. X-ray diffraction, SEM-AFM, and Raman spectrometer were used to study the effect of dopant content on structural, surface morphological, vibrational, and optical properties. The XRD analysis verified zinc oxide’s hexagonal wurtzite crystal structure. Wavy-like cluster formation was seen in the SEM images. The Raman and XRD measurements indicated that introducing Rb impurities into the ZnO host lattice resulted in a deterioration in crystal quality due to lattice stress. Optical spectra showed a blue shift in the bandgap. In addition, the antibacterial activity against E. coli and contact angle measurements were also investigated. The increase in dopant concentration resulted in a change from a hydrophilic to a hydrophobic nature, and all samples demonstrated significant antibacterial activity against E. coli. Graphical Abstract Highlights Al and Rb doped ZnO thin films were fabricated using the sol–gel dip coating technique. Changing dopant concentrations affected ZnO crystallinity. The synthesized films revealed grains with a wavy texture. Increasing contact angle shows hydrophobicity. The antibacterial activity of deposited films against E. coli bacteria improved.