Enhanced sensitivity of zinc phthalocyanine-based microporous humidity sensors by varying size of electrode gaps
Document Type
Article
Publication Date
9-15-2021
Abstract
The use of organic materials has become an increasingly important issue in sensing devices in recent times. Phthalocyanine is among the most promising materials in this undertaking. Zinc phthalocyanine (ZnPc) based microporous device was fabricated and its capacitance was utilized as the sensing mechanism for a humidity sensor. The effect of the electrode gap of the device on the electrical properties was investigated along with the correlation between the device's performances and the morphology of the sensing film. Using the solutionprocessed spin coating method, the capacitive type humidity sensor devices have been fabricated in a planar geometry of Al/ZnPc/Al with the presence of a microporous template. The size of electrode gaps measured with a surface profiler was 53.00 +/- 0.06 mu m, 119.00 +/- 0.03 mu m and 286.00 +/- 0.01 mu m. The surface morphology was characterized by using transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS). Analysis of the experimental results showed that the device with the shortest electrode gap (53.00 mu m) produced the best sensitivity of 1.03 +/- 0.04 pF/%RH than that of the longer gaps. Additionally, hysteresis as well as response and recovery performances have also been investigated.
Keywords
ZnPc, Organic, Microporous, Electrode gaps, Humidity sensor
Divisions
Science
Funders
Ministry of Higher Education Malaysia under the Fundamental Research Grant Scheme[FP078-2018A],University of Malaya under the RU grant[GPF080A-2020],Synchrotron Light Research Institute, Thailand
Publication Title
Sensors and Actuators B-Chemical
Volume
343
Publisher
Elsevier Science SA
Publisher Location
PO BOX 564, 1001 LAUSANNE, SWITZERLAND