Solution-processable and photopolymerisable TiO2 nanorods as dielectric layers for thin film transistors

Fei Cheng; Emanuele Verrelli; Fahad A Alharthi; Satyajit Das; Thomas D Anthopoulos; Khue T Lai; Neil T Kemp; Mary O'Neill; Stephen M Kelly

doi:10.1039/d0ra04445h

Solution-processable and photopolymerisable TiO₂ nanorods as dielectric layers for thin film transistors

RSC Adv. 2020 Jul 6;10(43):25540-25546. doi: 10.1039/d0ra04445h. eCollection 2020 Jul 3.

Authors

Fei Cheng¹, Emanuele Verrelli², Fahad A Alharthi^{1

3}, Satyajit Das⁴, Thomas D Anthopoulos^{4

5}, Khue T Lai⁶, Neil T Kemp², Mary O'Neill⁷, Stephen M Kelly¹

Affiliations

¹ Department of Chemistry & Biochemistry, University of Hull Cottingham Road Hull HU6 7RX UK s.m.kelly@hull.ac.uk.
² Department of Physics & Mathematics, University of Hull Cottingham Road Hull HU6 7RX UK.
³ Department of Chemistry, College of Science, King Saud University P. O. Box 2455 Riyadh 11451 Saudi Arabia.
⁴ Centre for Plastic Electronics, Department of Physics, Blackett Laboratory, Imperial College London London SW7 2BW UK.
⁵ King Abdullah University of Science and Technology (KAUST), KAUST Solar Centre Thuwal 23955-6900 Saudi Arabia.
⁶ Electronic Systems Design Centre, Energy Safety Research Institute, College of Engineering, Swansea University Bay Campus Swansea SA1 8EN UK.
⁷ School of Science & Technology, Nottingham Trent University 50 Shakespeare Street Nottingham NG1 3LL UK.

Abstract

We report the fabrication of a solution-processed n-type Thin Film Transistor (TFT) with current on/off ratios of 10⁴, a turn-on voltage (V _ON) of 1.2 V and a threshold voltage (V _T) of 6.2 V. The TFT incorporates an insoluble and intractable dielectric layer (k = 7-9) prepared in situ from solution-processed and then photopolymerised ligand-stabilised, inorganic/organic TiO₂ nanorods. A solution processed zinc oxide (ZnO) layer acts as the semiconductor. The new surface-modified TiO₂ nanorods were synthesised using a ligand replacement process with a monolayer coating of photopolymerisable 10-undecynylphosphonic acid (10UCYPA) to render them both soluble in common organic solvents and be photopolymerisable using UV-illumination after having been deposited on substrate surfaces from solution and drying.