Fan Ching-Lin, Tsao Hou-Yen, Shiah Yu-Shien, Yao Che-Wei, Cheng Po-Wei
Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, 43 Sec. 4, Keelung Road, Taipei 106, Taiwan.
Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology, 43 Sec. 4, Keelung Road, Taipei 106, Taiwan.
Polymers (Basel). 2021 Nov 15;13(22):3941. doi: 10.3390/polym13223941.
In this study, we proposed using the high-K polyvinyl alcohol (PVA)/low-K poly-4-vinylphenol (PVP) bilayer structure as the gate insulator to improve the performance of a pentacene-based organic thin-film transistor. The dielectric constant of the optimal high-K PVA/low-K PVP bilayer was 5.6, which was higher than that of the single PVP layer. It resulted in an increase in the gate capacitance and an increased drain current. The surface morphology of the bilayer gate dielectric could be suitable for pentacene grain growth because the PVP layer was deposited above the organic PVA surface, thereby replacing the inorganic surface of the ITO gate electrode. The device performances were significantly improved by using the bilayer gate dielectric based upon the high-K characteristics of the PVA layer and the enlargement of the pentacene grain. Notably, the field-effect mobility was increased from 0.16 to 1.12 cm/(Vs), 7 times higher than that of the control sample.
在本研究中，我们提议使用高介电常数的聚乙烯醇（PVA）/低介电常数的聚4-乙烯基苯酚（PVP）双层结构作为栅极绝缘体，以改善并五苯有机薄膜晶体管的性能。最佳高介电常数PVA/低介电常数PVP双层的介电常数为5.6，高于单一PVP层的介电常数。这导致栅极电容增加，漏极电流增大。双层栅极电介质的表面形态可能适合并五苯晶粒生长，因为PVP层沉积在有机PVA表面上方，从而取代了ITO栅极电极的无机表面。基于PVA层的高介电常数特性和并五苯晶粒的增大，使用双层栅极电介质显著改善了器件性能。值得注意的是，场效应迁移率从0.16提高到1.12 cm/(Vs)，比对照样品高7倍。
