Document Type : Research Paper


1 Laser and Optoelectronic Engineering Dept., University of Technology-Iraq, Alsina’a Street, 10066 Baghdad, Iraq.

2 College of Science Department of Physics, University of Baghdad, Baghdad, Iraq.


This paper presents the electrical behavior of the top contact/ bottom gate of an organic field-effect transistor (OFET) utilizing Pentacene as a semiconductor layer with two distinctive gate dielectric materials Polyvinylpyrrolidone (PVP) and Zirconium oxide (ZrO2) were chosen. The influence of the monolayer and bilayer gates insulator on OFET performance was investigated. MATLAB software was used to simulate and determine the electrical characteristics of a device. The output and transfer characteristics were studied for ZrO2, PVP and ZrO2/PVP as an organic gate insulator layer. Both characteristics show a high drain current at the gate dielectric ZrO2/PVP equal to -0.0031A and -0.0015A for output and transfer characteristics respectively, this can be attributed to an increase in the dielectric capacitance. Trans conductance characteristics also studied the gate dielectric materials and show the ZrO2/PVP gate dielectric having a higher value from the monolayer, indicating the effect of dielectric capacitance.


  • Modeling of Organic field effect transistors were conceded.
  • Focusing on the effect of dielectric materials on the OFET performance.
  • Comparison between two different dielectric materials (PVP, ZrO2) was considering.
  • I-V characteristics were analyzed and studied. 


Main Subjects

[1] J. L. Brédas, J. P. Calbert, D. A. Da Silva Filho, and J. Cornil, Organic semiconductors: A theoretical characterization of the basic parameters governing charge transport, Proc. Natl. Acad. Sci. U. S. A., 99, (2002), 5804–5809, doi: 10.1073/pnas.092143399.
[2] Y. Yamashita, Organic semiconductors for organic field-effect transistors, in science and technology  of advanced materials, 10, (2009), 1–9, doi: 10.1088/1468-6996/10/2/024313.
[3] J. K. A. Kokil and K. Yang, Techniques for characterization of charge carrier mobility in organic semiconductors, J. Polym. Sci. PART B Polym. Phys., 50, (2012), 1130–1144, doi: 10.1002/polb.23103.
[4] M. A. Najeeb, Z. Ahmad, and R. A. Shakoor, Organic thin-film capacitive and resistive humidity sensors : A Focus Review, Adv. Mater. Interfaces, 1800969, (2018), 1–19, doi: 10.1002/admi.201800969.
[5] B. K. Periyasamy, S. K. Nayak, S. A. Kumar & J. S. Shankar, Device engineering aspects of organic light- emitting diodes (OLEDs), Polym. Technol. Mater., 58, (2019), 1597–1624, doi: 10.1080/25740881.2018.1563133.
[6] N. Karl, Charge carrier transport in organic semiconductors, Synth. Met., 134, (2003), 649–657.
[7] M. T. Hussein, E. K. Hassan, and E. T. And Abdullah, Study the high performance of organic semiconductor CuPc field effect transistor, ( 2015). [Online]. Available:
[8] S. P.Haridas, S. Sreeshan, S. P. Jacob, S. Khan, and  and C. R. Azariah, Fabrication and characterization of flexible metal-insulator- semiconductor field effect transistor (MISFET) using organic ODS and inorganic ZrO2 as dielectric stack materials, Int. J. Trend Res. Dev., 4, (2017), 345–347.
[9] L. Z. Y. Ran, T. F. H.YuFeng, C.ShaoBo, and H. Y. A. L. XiaoJun, Effects of gate dielectric thickness and semiconductor thickness on device performance of organic field-effect transistors based on pentacene, Sci. CHINA Technol. Sci., 57, (2014), 1142–1146.
[10] A. Assis, S. H. T. A, and P. Predeep, Organic field  effect transistors – study of performance parameters for different dielectric layer thickness, in AIP Conference Proceedings, 1849, (2017), 020034.
[11] S. Hall, O. Buiu, I. Mitrovic, Y. Lu, and W. Davey, Review and perspective of high-k dielectrics on silicon, J. Telecommun. Inf. Technol., ( 2007), 33–43.
[12] K. C. Y. Lu, W. H. Lee, H. S. Lee, and Y. Jang, Low-voltage organic transistors with titanium oxide-polystyrene bilayer dielectrics, Appl. Phys. Lett., 94, (2009), 1–3, doi: 10.1063/1.3097010.
[13] B. H. Mohammed and E. T. Abdullah, Comparison between horizontal and vertical OFETs by using poly (3-Hexylthiophene) (P3HT) as an active semiconductor layer, Iraqi J. Sci., 61, (2020), 1040–1050, doi: 10.24996/ijs.2020.61.5.13.
[14] B. G. Horowitz, Organic Field-Effect Transistors, Adv. Mater., 10, (1998), 365–377.
[15] B. Thokchom, F. Meghdadi, S. Gues, N. Marjanovic, G. Horowitz, P. Lang, S. Bauer and N. S. Sariciftci, High-performance ambipolar pentacene organic field-effect transistors on poly (vinyl alcohol) organic gate dielectric, Advanced Materials,  (2005), 2315–2320, doi: 10.1002/adma.200501109.
[16] B. H. Mohammed and E. T. Abdullah, Study the performance of pentacene based organic field effect transistor by using monolayer, bilayer and trilayer with different gate insulators, Iraqi J. Phys., 18, (2020), 85–97, doi: 10.20723/ijp.18.44.85-97.
[17] M. A. Demir, A. Atahan, S. Baʇci and  and M. S. I. Aslan, Organic/inorganic interfaced field-effect transistor properties with a novel organic semiconducting material, Philos. Mag., 96, (2016), 274–285, doi: 10.1080/14786435.2015.1130277.