Effect of Trap Energy on Series Resistance of Phenosafranine Dye Based Organic Diode in Presence of TiO<sub>2</sub> and ZnO Nanoparticles

Abstract

The series resistance (Rs) controls the device performance significantly and for organic diode, the typical value of Rs is quite high. There are not many reports on the investigation of the high value of resistance in organic diodes. In this paper, we report that the trapping of charge carriers which is an important parameter to control the charge transport mechanism in organic solids is responsible for this high value of series resistance. In this paper effect of trap energy on Rs has been studied in the presence of TiO2 and ZnO nanoparticles on Phenosafranine (PSF) dye-based organic diode. It is already reported that by incorporating nanoparticles, trap energy is reduced which in turn increases the conductivity and efficiency of the device. So it is expected that trap energy has a strong influence on Rs. In this work we have measured Rs by using the Cheung Cheung method and the trap energy is also measured by analyzing the dc current. The value of Rs is related to trap energy. The extracted values of Rs are about 250.8 KΩ, 108.0 KΩ, and 98.4 KΩ respectively for only PSF, PSF+ZnO, and PSF+TiO2. It is also been observed that by incorporating nanoparticles the trap energy is reduced. The estimated values of the trap energy are about 0.090eV, 0.078eV ,0.072eV respectively for only PSF, PSF+ZnO, and PSF+TiO2. It has been observed that lowering of trap energy by incorporating TiO2 and ZnO reduces the value of Rs.