Development of an organic resistive-type humidity sensor

Abstract

In this paper, the humidity sensing characteristics of an organic semiconductor Zn (II) tetra 5,10,15,20 phenyl-porphyrin (ZnTPP) have been investigated. The ZnTPP film was deposited by a spin-coating on glass substrate with pre-deposition of silver interdigital electrodes. The performance of the porphyrin humidity sensor was analysed through electrical resistance and conductance measurements at various humidity level. It was observed that the change in resistance at 20 Hz is about 816 times with increasing the relative humidity from 0% to 98% at 25°C. The response and recovery time of the sensor were about 80 and 130 s, respectively.