title: Modulating Cationic Ratios for High-Performance Transparent Solution-Processed Electronics.
abstract: Amorphous oxide semiconductors such as indium zinc tin oxide (IZTO) are considered favorites to serve as channel materials for thin film transistors (TFTs) because they combine high charge carrier mobility with high optical transmittance, allowing for the development of transparent electronics. Although the influence of relative cationic concentrations in determining the electronic properties have been studied in sputtered and PLD films, the development of printed transparent electronics hinges on such dependencies being explored for solution-processed systems. Here, we study solution-processed indium zinc tin oxide thin film transistors (TFTs) to investigate variation in their electrical properties with change in cationic composition. Charge transport mobility ranging from 0.3 to 20.3 cm(2)/(V s), subthreshold swing ranging from 1.2 to 8.4 V/dec, threshold voltage ranging from -50 to 5 V, and drain current on-off ratio ranging from 3 to 6 orders of magnitude were obtained by examining different compositions of the semiconductor films. Mobility was found to increase with the incorporation of large cations such as In(3+) and Sn(4+) due to the vast s-orbital overlap they can achieve when compared to the intercationic distance. Subthreshold swing decreased with an increase in Zn(2+) concentration due to reduced interfacial state formation between the semiconductor and dielectric. The optimized transistor obtained at a compositional ratio of In/Zn/Sn = 1:1:1, exhibited a high field-effect mobility of 8.62 cm(2)/(V s), subthreshold swing of 1.75 V/dec, and current on-off ratio of 10(6). Such impressive performances reaffirm the promise of amorphous metal oxide semiconductors for printed electronics.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , Singapore 637553.
authors.forename: Rohit Abraham
authors.initials: RA
authors.lastname: John
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , Singapore 637553.
authors.forename: Anh Chien
authors.initials: AC
authors.lastname: Nguyen
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , Singapore 637553.
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , Singapore 637553.|Energy Research Institute@NTU (ERI@N), Interdisciplinary Graduate School , Singapore 637553.
authors.forename: Sudhanshu
authors.initials: S
authors.lastname: Shukla
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences , Singapore 637371.
authors.forename: Shi
authors.initials: S
authors.lastname: Chen
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , Singapore 637553.|Energy Research Institute@NTU (ERI@N), Nanyang Technological University , Singapore 637553.
authors.forename: Nripan
authors.initials: N
authors.lastname: Mathews
keywords: activation energy; indium zinc tin oxide; mobility; on−off ratio; printed electronics; thin film transistors