• Charge transport studies of highly stable diketopyrrolopyrrole-based molecular semiconductor

• Fulltext

https://www.ias.ac.in/article/fulltext/boms/045/0242

• Keywords

Diketopyrrolopyrrole; conduction mechanism; impedance spectroscopy; ambient stable; AC conductivity.

• Abstract

In the last decade, the diketopyrrolopyrrole (DPP)-based molecular semiconductors received significant prominence for its ability to build ambient stable donor–acceptor type organic materials for numerous microelectronics applications, especially in organic thin-film transistors and photovoltaics. This research article demonstrates the charge transport properties of 3,6-bis(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2,5-dihexadecylpyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione[DPP(PhNMe$_2$)$_2$] in single layer device structure prepared by thermal evaporation technique in the frequency and temperature range of 10$^2$–10$^6$ Hz and 133–273 K, respectively. An initial impression of Nyquist plot suggests metal-like behaviour as the impedance increases with an increase in temperature. Semicircle in Nyquist plot suggests Debye-type relaxation. This result has been explained mathematically and fitted equivalent circuit (contact resistance + parallel combination of resistance and capacitance) of device. Resonance frequency have been estimated by the Nyquist plot and crosschecked by Joncher’s Power Law. The frequency exponent ‘s’ is estimated by Joncher’s Universal Power Law and it further shows that charge transport mechanism in the device is quantum mechanical tunnelling. These analyses indicate the existence of Poole–Frenkel effect and explains the charge carrier mobility dependence on the applied field in the studied temperature range.

• Author Affiliations

1. Department of Electronics and Communication Engineering, Guru Jambheshwar University of Science and Technology, Hisar 125001, India
2. Organic and Hybrid Solar Cell Group, National Physical Laboratory, New Delhi 110012, India
3. School for Advanced Research in Polymers, Central Institute of Petrochemicals Engineering and Technology, Bhubaneswar 751024, India
4. Department of Physics, Maharshi Dayanand University, Rohtak 124001, India
5. School of Engineering and Technology, Central University of Haryana, Mahendragarh 123031, India

• Bulletin of Materials Science

Volume 46, 2023
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• Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020