A study on the dielectric non-Debye relaxation and ac and dc conductivity characteristics in nanostructured film of 2,7,12,17-tetra-tert-butyl-5,10,15,20-tetraaza-21H,23H-porphyrin
Department of Physics, Faculty of Science, University of Tabuk, 71491, Tabuk, Saudi Arabia
2 Nanotechnology Research Unit, Faculty of Science, University of Tabuk, 71491, Tabuk, Saudi Arabia
3 Department of Physics, Faculty of Education at Al-Mahweet, Sana’a University, Al-Mahweet, Yemen
Accepted: 28 July 2021
Published online: 6 August 2021
Porphyrin compounds have gained significant attention and proposed technical applications, including gas sensors and optoelectronic systems. One of them is 2,7,12,17-tetra-tert-butyl-5,10,15,20-tetraaza-21H,23H-porphyrin (TTBTP) which is a highly structured organic semiconductor in thin films. Thin TTBTP films have been produced using the vacuum thermal evaporation technique. Testing for X-ray diffraction reveals that TTBTP films are nanostructured, with an average grain size of 56 nm. The conduct against frequency (40 Hz–5 MHz) and temperature (303–373 K) of the complex dielectric constant was investigated. Further, the relationship between the complex electric module and the frequency at different temperature values has been discussed. The relaxation activation energy has been calculated as 0.156 eV, and the relaxation process is defined as non-Debye for TTBTP film. Jonscher's formalism clarified the action of conductivity in the higher frequency range. Within the TTBTP film, the transfer of carrier charge was controlled by the corresponding correlated barrier hopping model. Moreover, the obtained rise of frequency indicates a decrease in the activation energy values of AC conduction.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021