Effect of Dye Concentration on Series Resistance of Thionin Dye-Based Organic Diode

Abstract

The series resistance (Rs) plays a significant role in the organic device performance. The typical value of Rs in any organic device is very high which is mainly because of the interface and the trapping of charge carriers at the bulk and also at the barrier potential at the interface. In this work, we have prepared Thionin dye-based organic diode and studied Rs by varying the dye concentration of the diode. To prepare this diode a thin layer of Thionin dye of different concentrations of 2 mg, 4 mg, 6 mg, and 8 mg are sandwiched separately in between two electrodes one of which is ITO coated glass and another is Al. The dark current-voltage (I–V) 120characteristics of these diodes have been studied and estimated the values of Rs by using Cheung Cheung function. It is observed that the estimated value of Rs for 2 mg is very high and by increasing the dye concentration, the value of Rs is reduced. It is also observed that the value of the ideality factor (η) also reduced by increasing the dye concentration.