In-Depth Optical Analysis of Zn(Al)O Mixed Metal Oxide Film-Based Zn/Al-Layered Double Hydroxide for TCO Application

Abstract

In this article, an in-depth optical investigation of Zn(Al)O-mixed metal oxide (MMO) film using Zn/Al-layered double hydroxide (LDH) was elucidated through co-precipitation and spin coating techniques. The field emission scanning electron microscopy (FE-SEM) analysis revealed the occurrence of a vertically aligned sheet-like structure with a thickness of 60 nm for pristine LDH, which further reduced to 45 nm after calcination at 300 °C. Additionally, pristine LDH showed multiple optical bandgaps of 5.18, 3.6, and 3.2 eV. Moreover, a good agreement of the obtained optical bandgaps was attained between both utilized methods, ultraviolet-visible light (UV-Vis), and photoluminescence (PL) spectroscopies. The optical bandgap decreased at higher calcination temperatures, which indicates the active role of the applied post-fabrication process on the optical profile of the deposited MMO film/s. The demonstrated transmittance spectra of the deposited MMO films exhibited a transparency between 85% and 95%; this indicates the usefulness and consistency of the proposed film for transparent conductive oxide (TCO) based optoelectronic applications.