Ultrasonic sol-gel dip coating of multilayer niobium-doped ZnO thin films: Analysis of optical properties

• Published in: Materials Letters
• Main Author: Eswar K.A.; Guliling M.; Khusaimi Z.; Rasmidi R.; Buniyamin I.; Rostan N.F.; Malek M.F.; Fadzilah Suhaimi M.H.; Mahmood M.R.; Abdullah S.
• Format: Article
• Language: English
• Published: Elsevier B.V. 2025
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85211036595&doi=10.1016%2fj.matlet.2024.137836&partnerID=40&md5=a596b60af0adc6d8306929ab7d7a0676

This study investigates the synthesis of multilayer Nb-doped ZnO thin films using an ultrasonic-assisted sol–gel dip-coating technique. The work aims to bridge a gap in the literature by examining the influence of multilayer deposition on optical and structural properties, which has not been extensively reported. The films demonstrate over 95 % transmittance in the visible range and increased absorption in the ultraviolet region. The six-layered thin film exhibited the highest optical performance, attributed to uniform particle size distribution and minimal structural defects. UV–vis spectroscopy revealed an optical bandgap ranging from 3.26 to 3.69 eV, while FESEM analysis indicated an average particle size of 24.8–25.2 nm. EDAX confirmed successful niobium doping, and XRD patterns identified a hexagonal wurtzite crystalline structure with a predominant (002) orientation. These findings highlight the potential of the ultrasonic sol–gel dip-coating method in fabricating high-quality optical thin films. © 2024 Elsevier B.V.