Analysis of the electrical characteristics of the Ag/ZnO Schottky barrier diodes on F-doped SnO2 glass substrates by pulsed laser deposition

High quality semiconductor layer of n-type ZnO thin film was fabricated on F-doped SnO2 glass substrates by pulsed laser deposition. The Schottky junction diodes with configuration of Ag/ZnO/FTO have been fabricated to study the devices electrical properties by current-voltage (I-V) and capacitance-voltage (C-V) measurements. The results show that the devices have good rectifying behaviors with an ideality factor of 1.64 and a Schottky barrier height of 0.85 eV based on the I-V characteristics. Also, Cheung's functions and Norde's method were used to evaluate the I-V characteristics and to obtain the series resistance of the Schottky contact. From the C-V characteristics, the capacitance was determined to increase with decrease of frequencies. C-V measurements have resulted in higher barrier heights than those obtained from I-V measurements. The discrepancy between Schottky barrier heights obtained from I-V and C-V measurements was also interpreted. (C) 2011 Elsevier B.V. All rights reserved.