Organic Capacitive-Resistive Humidity Sensor Based On Al/MgPc/PEDOT:PSS/Al at Room Temperature

Abstract

The present study is aimed to fabricate an organic humidity sensor Al/MgPc/PEDOT:PSS/Al using  (MgPc) with  various amounts of PEDOT:PSS (0, 0.25, 0.5, 0.75, and 1 w/w) on glass substrates. Drop-casting technique was utilized to prepare thin films of MgPc/PEDOT:PSS and the produced films were thermally treated to annealing temperature of 423 K.  The effect of humidity on the electrical properties of the nanocomposite film was investigated by measuring the capacitance and the dissipation of the samples at four different frequencies of the applied voltage. The dissipation measurements were used to determine the resistances of the samples. It is observed that the capacitance of the sensor increased with decreasing the resistance when the relative humidity rises. It was also found that the values of capacitance and resistance decreased with increasing the frequency. The experimental results were supported by the simulation of the resistance/capacitance – humidity relationship.