Study on the electrical and the optical properties of ZnO grown by using Pulsed laser deposition

Abstract

Pulsed laser deposition (PLD) was used to fabrication of ZnO films on a sapphire substrates. We modulated some parameters, such as the temperature and the gas pressure, to find the best growth conditions. After the growth, the ZnO films were characterized by using X-ray diffraction, photoluminescence (PL), and capacitance-voltage (C-V) measurements. The PL spectra had higher intensities for the ZnO films grown at low temperatures, and the number of defect states was fewer. However, based on the scanning electron microsope (SEM) images, the crystallinity of ZnO deposited at a high substrate temperature was better than that of the ZnO deposited at low temperature, and the grain size shows smaller at a high growth temperature. From the C-V measurements of the ZnO film, the ZnO thin film showed typical semiconductor properties. Thus, we confirmed that the ZnO films deposited by using PLD had relatively good semiconductor properties in the optical and the electrical regions.