The ultraviolet responses of ZnO-based thin-film transistor prepared by sol-gel method

• Published in: Materials research innovations Vol. 19; no. sup10; pp. S10-382 - S10-386
• Main Authors: Zhang, M., Yu, Z. N., Wang, J. Z., Xue, W.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 31.12.2015
• Subjects: Channels; Illumination; photodetector; Semiconductor devices; Sol gel process; sol-gel method; Thin film transistors; thin-film transistor; Threshold voltage; Ultraviolet; Zinc oxide; ZnO
• ISSN: 1432-8917; 1433-075X
• DOI: 10.1179/1432891715Z.0000000002202

Bottom-gate and top-contact thin-film transistors with ZnO film as a channel layer were fabricated by sol-gel method. The structural and optical properties of the deposited ZnO films were investigated through X-ray diffractometer, scanning electron microscopy and UV-Vis spectrophotometer. ZnO film has a high absorption in the ultraviolet region and c-axis orientation normal to the substrate. The on/off current ratio, channel mobility and threshold voltage of ZnO-based thin-film transistors in dark are 10 5 , 0·02 cm 2 V −1 s −1 and 8·3 V, respectively. Under UV light illumination (λ = 365 nm) with an intensity of 2·4 μW/cm 2 , the drain-source current I DS of thin-film transistor dramatically increases and the photo-to-dark current ratio is greater than 10 4 . The transient response of the device to ultraviolet illumination is also discussed. The results may open the possibility of employing ZnO-thin-film transistors as UV photodetector.