Current transport studies and extraction of series resistance of Pd/ZnO Schottky diode

Electrical characterization of Palladium (Pd) Schottky diodes on n-type zinc oxide (ZnO) is performed by current-voltage (I-V) and capacitance-voltage (C-V) and current-voltage-temperature (I-V-T) measurements. Single crystal bulk ZnO wafer synthesized hydrothermally in the wurtzite (0001) orientation has been used for device fabrication. From I-V measurements the Schottky diodes exhibited a non-linear rectifying behavior with a barrier height of 0.65eV and an ideality factor of 4.1. Room temperature current transport mechanism has been investigated from logI - logV plot. Series resistance (R_s) is extracted from forward I-V characteristics by using Chueng function and Norde function. R_s is also extracted from I-V-T measurements at two different temperatures, by using modified Norde function. The series resistance is found in the range from 313 to 460 Ω. A comparison is made between the obtained values of Series resistances and possible reasons of discrepancy are addressed.