Affiliation:
1. Department of Physics Faculty of Mathematics and Natural Sciences Universitas Andalas Padang 25163 West Sumatera Indonesia
2. Department of Chemistry Faculty of Mathematics and Natural Sciences Universitas Andalas Padang 25163 West Sumatera Indonesia
Abstract
AbstractZnO thin films were prepared by sol‐gel spin coating on a glass substrate via green synthesis using Uncaria gambir leaf extract. The deposited films were characterized for structural, morphological, and optical properties at various annealing temperatures (400, 500, and 600 °C). The ZnO film without annealing shows an amorphous structure, and after annealing, it shows a hexagonal wurtzite structure with a dominant (101) peak. The crystallinity of the films increases up to 500 °C. The crystallite size shows a maximum value (27 nm) at 500 °C. Also, a flat, smooth, uniform wrinkle and the homogenous surface of ZnO thin films are shown at 500 °C. The gambir extract prevents the segregation of crystallites until 500 °C. The transparency was over 80 % in the visual region for all annealed films, and the energy bandgap decreased to 3.81 eV with increasing the annealing temperature up to 500 °C.