Hostname: page-component-8448b6f56d-sxzjt Total loading time: 0 Render date: 2024-04-19T00:50:30.363Z Has data issue: false hasContentIssue false

OFET Sensors with Poly 3-hexylthiophene and Pentacene as Channel Materials for Ionizing Radiation

Published online by Cambridge University Press:  07 February 2012

Harshil N. Raval
Affiliation:
Centre of Excellence in Nanoelectronics, Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai – 400 076, India.
V. Ramgopal Rao
Affiliation:
Centre of Excellence in Nanoelectronics, Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai – 400 076, India.
Get access

Abstract

Pentacene and poly 3-hexylthiophene (P3HT) are the most promising p-type organic semiconducting materials for fabrication of organic field effect transistors (OFETs). OFETs with aforesaid organic semiconducting materials have been demonstrated as total dose detectors for ionizing radiation, wherein the changes in the electrical characteristic parameters, such as, increase in the OFF current, increase in the ON current, change in the current ratio, shift in the threshold voltage, change in the subthreshold swing, etc., were used as a measure of ionizing radiation dose. Upon exposure to ionizing radiation P3HT based OFET sensor has shown an OFF current sensitivity of 4.4 nA/Gy while pentacene based OFET sensor has shown an OFF current sensitivity of 26.7 nA/Gy for a total of 50 Gy dose of ionizing radiation. Change in the conductivity of the thin-films of pentacene and P3HT were observed and compared using electrostatic force microscopy (EFM) imaging before and after exposure to ionizing radiation. Effects of ionizing radiation on the energy band structures of the organic semiconducting materials, pentacene and P3HT, have been studied using UV-visible spectroscopy. Moreover, analysis of UV-visible spectra of the thin-films suggested the generation of energy states in larger quantity in case of pentacene thin-film as compared to P3HT thin-film upon exposure to the same dose of ionizing radiation. These results confirm the higher sensitivity observed in pentacene OFET sensor as compared to P3HT OFET sensor in terms of the change in electrical parameters.

Type
Research Article
Copyright
Copyright © Materials Research Society 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Guillaud, G., Simon, J., Germain, J. P., Coord. Chem. Rev. 178 (2), 1433 (1998).Google Scholar
2. Dudhe, R. S., Sinha, J., Kumar, A., Rao, V. R., Sens. and Actu. B: Chem. 148 (1), 158 (2010).Google Scholar
3. Raval, H. N., Tiwari, S. P., Navan, R. R., Rao, V. R., Appl. Phys. Lett. 94 (12), 123304 (2009).Google Scholar
4. Raval, H. N. and Rao, V. R., IEEE Elect. Dev. Lett. 31 (12), 14821484 (2010).Google Scholar
5. Raval, H. N. and Ramgopal Rao, V., MRS Proceedings, 1312, mrsf10-1312-hh03-10 (2011).Google Scholar
6. Lobez, J. M., and Swager, T. M., Chem. Int. Ed. 49 (1), 9598 (2010).Google Scholar
7. Crone, B., Dodabalapur, A., Gelperin, A., Torsi, L., Katz, H. E., Lovinger, A. J., Bao, Z., Appl. Phys. Lett. 78 (15), 22292231 (2001).Google Scholar
8. Dimitrakopoulos, C. D., Malenfant, P. R. L., Adv. Mater. 14 (2), 99 (2002).Google Scholar
9. Tsukagoshi, Kazuhito, Tanabe, Jun, yagi, Iwao, Shigeto, Kunji, Yanagisawa, Keiichi, aoyagi, Yoshinobu, J. Appl. Phys. 99, 064506 (2006).Google Scholar
10. Raval, H. N., Tiwari, S. P., Navan, R. R., Mhaisalkar, Subodh G., Rao, V. R., IEEE Elect. Dev. Lett. 30 (5), 484486 (2009).Google Scholar
11. Tiwari, S. P., Srinivas, P., Shriram, S., Kale, N. S., Mhaisalkar, S. G. and Ramgopal Rao, V., Thin Solid Films, 516 (5), 770772 (2008).Google Scholar