ZnTTP electrical properties and application in humidity sensor development

摘要

In the present work, the alternative current (ac) electrical properties of 5, 10, 15, 20 tetrato-loylphenylporphyrinato zinc (II) (ZnTTP) spin coated thin films have been investigated and discussed using existing physical models. The electrical measurement results show conduction mechanism within the thin film which is most probably due to hopping of charge carriers through trap sites. At room temperature, the resistive responses were measured in different relative humidity (RH) levels ranging from 0% to 98% and at various frequencies varying from 20 Hz to 20 MHz. The resistance is enhanced of 816 times at 20 Hz in the entire RH range. The develop humidity ZnTTP based sensor exhibits a linear response, high sensitivity and low hysteresis. Furthermore, ZnTTP based sensor has the response and recovery times of 36 s and 239 s, respectively.