SYNTHESIS AND ELECTROCHEMICAL STUDIES OF CONJUGATEDLY LINKED MULTIPORPHYRINS AND THEIR METAL COMPLEXES

Abstract

In this study, an organic semiconductor 5,10, 15,20-tetrakis(4 0 -isopropylphenyl) porphyrin (TIPP) was synthesized and investigated as an active material in sur- face-type multifunctional sensor. As electrodes, 100 nm thick Ag films were deposited on 25 mm 9 25 mm glass substrate with 40 lm gap between them. Thin film of TIPP of area 15 mm 9 15 mm was thermally sublimed to cover the gap between the silver electrodes. Thickness of TIPP film was 100 nm. A change in electrical resistance and capacitance of the fabricated device was observed with the increase in relative humidity (RH), temperature, and illu- mination. Hysteresis, response, and recovery times were investigated over a wide range of RH (0–94%). Activation energy of the TIPP was estimated. An equivalent circuit of the Ag/TIPP/Ag humidity, temperature, and illumination sensor was developed. Humidity, temperature, illumination dependent capacitive, and resistive properties of this sensor make it promising for use in a humidity, temperature, and lux multi-meters.