Porous zinc oxide nanocrystalline film deposition by atmospheric pressure plasma: fabrication and energy band estimation

Porous ZnO nanocrystalline films have drawn research attention due to improvement in gas sensing, adsorption, photocatalytic, and photovoltaic applications. However, scalable synthesis of porous nanostructures has been a challenge. Here, This paper reports a very easy, fast, and scalable one-step process for synthesis and deposition of porous ZnO nanocrystalline film by low-temperature atmospheric pressure plasma. The plasma is generated with radio frequency power using a metallic zinc wire as a precursor. Nanostructures have been synthesized and agglomerate to form a porous film at the substrate. Energy band structure of the deposited film has been investigated to understand the corresponding band alignment, which is relevant to many applications. An in-depth study of the grown nanostructured ZnO film has been included and characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, kelvin probe measurement, ultra-violet/visible absorption, and photoluminescence.