Reducing Trap States in Printed Indium Zinc Oxide Transistors by Doping with Benzyl Viologen

• Published in: Advanced electronic materials Vol. 4; no. 5
• Main Authors: Kim, Hyonwoong, Ng, Tse Nga
• Format: Journal Article
• Language: English
• Published: 01.05.2018
• Subjects: charge‐transfer doping; indium zinc oxide; interface states; printed thin‐film transistors
• ISSN: 2199-160X; 2199-160X
• DOI: 10.1002/aelm.201700631

An air‐stable, strongly reducing molecule benzyl viologen (BV) is used to induce charge‐transfer doping of the indium zinc oxide semiconductor in inkjet‐printed thin‐film transistors. The device mobility is improved from 5.8 ± 1.4 cm2 V−1 s−1 in the undoped devices and reached up to 8.7 ± 1.0 cm2 V−1 s−1 after BV treatment. Through measurement of frequency‐dependent admittance and capacitance, this work quantifies the density of interface states and shows that interfacial trap density is four times lower in the BV‐doped transistors compared to undoped devices. Application of strong reducing agent benzyl viologen (BV) in printed indium zinc oxide (IZO) is demonstrated and analyzed by frequency‐dependent admittance and capacitance methods. It is shown that charger transfer doping with BV is an efficient way to enhance device stability and carrier transport in printed IZO thin‐film transistors.