“…However, these methods are often complex and require costly vacuum equipment. In contrast, ZnO thin films can also be prepared via chemical methods, such as chemical bath deposition [12], chemical vapor deposition [13], atomic layer deposition [14], spray pyrolysis [15], printing [16], sol-gel spin coating [17], and electrochemical deposition [18], which are simpler methods and generally less costly. The conventional sol-gel method is often preferred over other chemical methods, due to its simplicity, lower crystallization temperature, and compositional control [19].…”