Zinc oxide (ZnO) is a compound that has unique physical and chemical properties. It has a direct band gap at 3.4 eV (without dopant), a high bonding energy (60 meV), and a high thermal and mechanical stability at room temperature. Thus, ZnO thin film can be suitably applied in many fields, and it also has many functions such as UV light emitters, hydrophobic coating, transparent thin film in electronic devices, piezoelectric material, transducers, gas-sensing, and a transparent conductive oxide (TCO) layer in thin film solar cells. ZnO thin film could be prepared by many chemical preparations such as chemical bat deposition (CBD), chemical vapor deposition (CVD), sol–gel spin coating, doctor blade, printing deposition, and electrochemical deposition (ED). This chemical process is a low-cost, simple, and easy preparation process to be adjusted or doped by other elements.
Part of the book: Emerging Solar Energy Materials