Studies of the Physical Properties of Sputter-Deposited ZnO, ZnO/Pt and ZnO/Pd Semiconductor Thin Films for Sensor Application

An investigation into the physical properties of the wide band gap oxide semiconductor material zinc oxide for sensors has been conducted. The investigation presented in this paper is divided into two sections. The first section focuses on the development of the deposition technology, investigation of physical properties (such as surface topography, crystalline structure, spectral transmission in the ultraviolet–visible–near infrared range, and the chemical composition) of the ZnO, ZnO/Pt, or ZnO/Pd layer. The other section focuses on the sensor's properties (changes in spectral transmission) of ZnO layers as a function of temperature or a selected gas environment (hydrogen). These investigations were carried out on the following structures: pure ZnO layer with a relatively low roughness surface, pure and porous ZnO layer, and porous ZnO layer doped with palladium or platinum. The results are a basis for the development of optoelectronic sensors, which serve the purpose of detecting hydrogen or temperature measurements.