Preparation of rare-earth thulium doped tin-oxide thin films and their applications in thin film transistors

Solution-processed zinc tin oxide (ZTO) thin-film transistors (TFTs) have great potential uses in next-generation wearable and flexible electronic products. Zinc and tin precursor materials are naturally abundant and have low fabrication costs. To integrate a single ZTO TFT into logic circuits including inverters, NAND, and NOR gates will require the development of a facile patterning process to replace conventional and complicated photolithography techniques which are usually time-consuming and toxic. In this study, self-patterned ZTO thin films were prepared using a photo-patternable precursor solution including a photoacid generator, (4-methylthiophenyl)methyl phenyl sulfonium triflate. Solution-processed ZTO precursor films fabricated with the photoacid generator were successfully micropatterned by UV exposure, and transitioned to a semiconducting ZTO thin film by heat treatment. The UV-irradiated precursor films became insoluble in developing solvent as the generated proton from the photoacid generator affected the metal-containing ligand and changed the solubility of the metal oxide precursors. The resulting ZTO thin films were utilized as the active layers of n-type TFTs, which exhibited a typical n-type transfer, and output characteristics with appropriate threshold voltage, on/off current ratio, and field-effect mobility. We believe that our work provides a convenient solution-based route to the fabrication of metal-oxide semiconductor patterns.

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Solution-processed semiconducting aluminum-zinc-tin-oxide thin films and their thin-film transistor applications

Ceramics International ◽

10.1016/j.ceramint.2013.12.127 ◽

2014 ◽

Vol 40 (6) ◽

pp. 7829-7836 ◽

Cited By ~ 9

Author(s):

Kyeong-Ah Kim ◽

Jun-Yong Bak ◽

Jeong-Seon Choi ◽

Sung-Min Yoon

Keyword(s):

Thin Film ◽

Thin Films ◽

Tin Oxide ◽

Thin Film Transistor ◽

Oxide Thin Films ◽

Solution Processed ◽

Zinc Tin Oxide

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Effects of Active Layer Thickness on the Electrical Characteristics and Stability of High-Mobility Amorphous Indium–Gallium–Tin Oxide Thin-Film Transistors

Electronics ◽

10.3390/electronics10111295 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1295

Author(s):

Dae-Hwan Kim ◽

Hyun-Seok Cha ◽

Hwan-Seok Jeong ◽

Seong-Hyun Hwang ◽

Hyuck-In Kwon

Keyword(s):

Thin Film ◽

Thin Films ◽

Layer Thickness ◽

Active Layer ◽

Tin Oxide ◽

Thin Film Transistors ◽

High Mobility ◽

Active Layer Thickness ◽

Electrical Characteristics ◽

Indium Gallium

Herein, we investigated the effects of active layer thickness (tS) on the electrical characteristics and stability of high-mobility indium–gallium–tin oxide (IGTO) thin-film transistors (TFTs). IGTO TFTs, with tS values of 7 nm, 15 nm, 25 nm, 35 nm, and 50 nm, were prepared for this analysis. The drain current was only slightly modulated by the gate-to-source voltage, in the case of the IGTO TFT with tS = 50 nm. Under positive bias stress (PBS), the electrical stability of the IGTO TFTs with a tS less than 35 nm improved as the tS increased. However, the negative bias illumination stress (NBIS) stability of these IGTO TFTs deteriorated as the tS increased. To explain these phenomena, we compared the O1s spectra of IGTO thin films with different tS values, acquired using X-ray photoelectron spectroscopy. The characterization results revealed that the better PBS stability, and the low NBIS stability, of the IGTO TFTs with thicker active layers were mainly due to a decrease in the number of hydroxyl groups and an increase in the number of oxygen vacancies in the IGTO thin films with an increase in tS, respectively. Among the IGTO TFTs with different tS, the IGTO TFT with a 15-nm thick active layer exhibited the best electrical characteristics with a field-effect mobility (µFE) of 26.5 cm2/V·s, a subthreshold swing (SS) of 0.16 V/dec, and a threshold voltage (VTH) of 0.3 V. Moreover, the device exhibited robust stability under PBS (ΔVTH = 0.9 V) and NBIS (ΔVTH = −1.87 V).

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