Impact of Post- Deposition Heat Treatment on the Morphology and Optical Properties of Zinc Oxide (ZnO) Thin Film Prepared by Spin-Coating Technique

Abstract

This research work examines the structural and optical properties of ZnO thin films. Deposition were done by spin coating of solution of Zinc oxide onto pre-cleaned glass substrate at 4000 rpm for 30 sec using spin-coater under ambient condition at room temperature in order to form desired thickness of the film on the substrate. Post-deposition thermal annealing at different range of temperatures from 150°C to 600°C with steps of 50°C was carried out on the samples. The impact of thermal annealing on optical properties of the deposited thin film was investigated using UV-VIS spectrophotometer and scanning Electron Microscope for the morphology. The optical transmittance, reflectance, absorbance were recorded which was used to evaluate the optical band gap of Zinc oxide. Observation shows that band gap energy reduces as annealing temperature is increased from 150°C to 600°C. Observation made on the morphology using SEM model ASPEX 3020 showed that as the temperature increases the surface of the sample roughness increases. It was deduced that as the annealing temperature is increased the surface roughness increases. This may be due to increase in grain size with increase in annealing temperature. The band gap energy decreases as the annealing temperature increases.

Synthesis and structural feasibility of photonic materials

“…This approach allows for the improvement of cold working qualities, ductility enhancement, material softening, internal stress relief, and ductility. (Sunday Wilson Balogun et al, 2017).…”

Дослідження Впливу Умов Синтезу На Оптико-Спектральні Властивості Високодисперсних Форм Оксиду Цинку

“…У літературі описано кілька способів синтезу ZnO з різною морфологією та характеристиками, включаючи хімічне осадження [12], сольвотермічний [13], золь-гель процес [14], термічне розкладання [15], мікрохвильове опромінення [16], покриття зануренням [17], покриття центрифугуванням [18], електричне осадження [19] та гідротермальна обробка [20]. Серед цих методів хімічне осадження є практичним способом недорогого та великомасштабного виробництва нанорозмірного ZnO і, як очікується, призведе до індустріалізації.…”

Experimental Design Modeling of the Effect of Hexagonal Wurtzite—ZnO Synthesis Conditions on Its Characteristics and Performance as a Cationic and Anionic Adsorbent

“…So far, many different ZnO structures such as flowers [1,12], needles [12], wires [13], rods [14,15,16], spheres [17,18], and stars [3,19] have been reported [1]. In addition to morphological structure, it is important for some applications to be able to control band gap energy for photocatalytic applications [17], particle size distribution [17,20,21], and zero point charge [22] for anionic and cationic adsorption applications.…”

“…Several ZnO synthesis routes have been described in the literature with different morphologies and excellent characteristics, including chemical precipitation [6], solvothermal [19], sol–gel processing [7], thermal decomposition [15], microwave irradiation [5], chemical bath deposition [4], dip coating [23], spin coating [20], electrical deposition [23], and hydrothermal processing [1,12,13,18,24,25,26]. Among these methods, hydrothermal processing has been proven to be a flexible approach to ZnO synthesis due to its simplicity, ease, and relatively low fabrication cost [11,24].…”