Ultraviolet Photodetecting and Plasmon-to-Electric Conversion of Controlled Inkjet-Printing Thin-Film Transistors

• Published in: Nanomaterials (Basel, Switzerland) Vol. 10; no. 3; p. 458
• Main Authors: Wang, Cheng-Jyun, You, Hsin-Chiang, Ou, Jen-Hung, Chu, Yun-Yi, Ko, Fu-Hsiang
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 04.03.2020; MDPI
• Subjects: Batch processing; Coffee; Contact angle; Conversion; Electrodes; Energy; ink-jet printing; Inkjet printing; Methods; Morphology; Nanoparticles; Oxygen plasma; oxygen plasma treatment; Photometers; Photoresponse; plasmon energy detection; Printing; Screen printing; Semiconductor devices; Semiconductor junctions; Semiconductor research; Silicon nitride; Temperature gradients; Thin film transistors; Thin films; Threshold voltage; Transistors; Ultraviolet radiation; visible light photodetection; Zinc; Zinc oxide; Zinc oxides; zinc-oxide-based thin-film transistors; Taiwan; plasmon energy detection; ink-jet printing; zinc-oxide-based thin-film transistors; oxygen plasma treatment; visible light photodetection
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano10030458

Direct ink-jet printing of a zinc-oxide-based thin-film transistor (ZnO-based TFT) with a three-dimensional (3-D) channel structure was demonstrated for ultraviolet light (UV) and visible light photodetection. Here, we demonstrated the channel structures by which temperature-induced Marangoni flow can be used to narrow the channel width from 318.9 ± 44.1 μm to 180.1 ± 13.9 μm via a temperature gradient. Furthermore, a simple and efficient oxygen plasma treatment was used to enhance the electrical characteristics of switching / ratio of approximately 10 . Therefore, the stable and excellent gate bias-controlled photo-transistors were fabricated and characterized in detail for ultraviolet (UV) and visible light sensing. The photodetector exhibited a superior photoresponse with a significant increase of more than 2 orders of magnitude larger drain current generated upon UV illumination. The results could be useful for the development of UV photodetectors by the direct-patterning ink-jet printing technique. Additionally, we also have successfully demonstrated that a metal-semiconductor junction structure that enables plasmon energy detection by using the plasmonic effects is an efficient conversion of plasmon energy to an electrical signal. The device showed a significant variations negative shift of threshold voltage under different light power density with exposure of visible light. With the ZnO-based TFTs, only ultraviolet light detection extends to the visible light wavelength.