ZnO thin-film transistors with a polymeric gate insulator built on a polyethersulfone substrate

• Published in: Solid-state electronics Vol. 69; pp. 27 - 30
• Main Authors: Hyung, Gun Woo, Park, Jaehoon, Koo, Ja Ryong, Choi, Kyung Min, Kwon, Sang Jik, Cho, Eou Sik, Kim, Yong Seog, Kim, Young Kwan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.03.2012; Elsevier
• Subjects: Applied sciences; Atomic layer deposition (ALD); Atomic structure; Electronics; Exact sciences and technology; Gates; Insulators; Plastic substrate; Polymeric insulator; Semiconductor devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Thin film transistors; Thin-film transistor; Threshold voltage; Transistors; Zinc oxide; Polymeric insulator; Zinc oxide; Thin-film transistor; Atomic layer deposition (ALD); Plastic substrate; Voltage threshold; Atomic layer method; Insulator; II-VI compound; Dielectric materials; Electric stress; Electron injection; Polycrystal; Polyvinylalcohol; Charge carrier trapping; Energy gap; Crosslinked polymer; Trapped electron; Thin film transistor; Plastics
• ISSN: 0038-1101; 1879-2405
• DOI: 10.1016/j.sse.2011.12.001

► ZnO active layer formed by means of atomic layer deposition. ► Poly(vinyl alcohol) as a solution-processed insulator. ► ZnO transistors built on a flexible polyethersulfone substrate. ► Trapped electrons at the insulator/ZnO interface caused a hysteresis. ► Injected electrons into the insulator caused a positive threshold voltage shift. Zinc oxide (ZnO) thin-film transistors (TFTs) with a cross-linked poly(vinyl alcohol) (c-PVA) insulator are fabricated on a polyethersulfone substrate. The ZnO film, formed by atomic layer deposition, shows a polycrystalline hexagonal structure with a band gap energy of about 3.37eV. The fabricated ZnO TFT exhibits a field-effect mobility of 0.38cm2/Vs and a threshold voltage of 0.2V. The hysteresis of the device is mainly caused by trapped electrons at the c-PVA/ZnO interface, whereas the positive threshold voltage shift occurs as a consequence of constant positive gate bias stress after 5000s due to an electron injection from the ZnO film into the c-PVA insulator.