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.
