Charge Carrier Distribution in Low-Voltage Dual-Gate Organic Thin-Film Transistors

Abstract

Dual-gate organic thin-film transistors (DGOTFTs), which exhibit better electrical properties, in terms of on-current and subthreshold slope than those of single-gate organic thin-film transistors (OTFTs) are promising devices for high-performance and robust organic electronics. Electrical behaviors of high-voltage (>10 V) DGOTFTs have been studied: however, the performance analysis in low-voltage DGOTFTs has not been reported because fabrication of low-voltage DGOTFTs is generally challenging. In this study, we successfully fabricated low-voltage (<5 V) DGOTFTs by employing thin parylene film as gate dielectrics and visualized the charge carrier distributions in low-voltage DGOTFTs by a simulation that is based on finite element method (FEM). The simulation results indicated that the dual-gate system produces a dual-channel and has excellent control of charge carrier density in the organic semiconducting layer, which leads to the better switching characteristics than the single-gate devices.

A Flexible, 2.4‐GHz Wireless Ion Sensor System Using Printed Organic Amplifiers with 3‐V Single Supply

“…Gain of the DG devices (≈30) was higher than that of the SG device (≈ 10) before the LED light exposure due to the second voltage bias. [ 32–35 ] Under the LED light, the gain decreased to 40% of the initial value for the SG devices, while 67% of the initial value for the DG devices was observed. Then, carrying out electrical measurements in dark again, the gain recovered up to 50% of the initial value for the SG devices, whereas 80% of the initial value for the DG devices was observed.…”

“…To improve electrical performances of the organic amplifiers, dual-gate (DG) structure was applied to the OTFT devices. Higher amplifier gain are expected by using DG structure than singlegate (SG), because applying a second voltage bias improves controllability of charge carrier density in organic semiconductor layers, [32] which enables improved transconductance [33] and drain current more saturated, [34] finally contributing to increase in gain of amplifiers. [34,35] On the other hand, we also expected improvement of operational stability under illumination because its two electrodes (bottom-and top-gate electrodes) act as lightshielding layers.…”

Low-Power Flexible Organic Field-Effect Transistors with Solution-Processable Polymer-Ceramic Nanoparticle Composite Dielectrics

“…As shown in Figure 4, the pentacene could grow in an orderly way on flat PVP film with large grain size, while the roughness of the film increases after mixing with high k CaTiO 3 NPs, resulting in the smaller and discontinuous grain size of the pentacene grown. The increased roughness reduces the carrier mobility of the associated device because of the increased barrier, which limits the hopping of charges in the channel region [21]. After PVP thin-film modification, fewer upheavals can be seen on the surface that lead to the surface roughness and surface energy of the dielectric layer decreasing, reducing from 1.07 nm, 43.9 mN/m to 0.79 nm, 38.6 mN/m, respectively.…”

Review—Advancements and Perspectives of Organic LED: In Depth Analysis of Architectural Design, Characteristics Parameters, Fabrication Techniques, and Applications

“…3 Recent advancement in dual gate TFTs is discussed here. In 2018, Shiwaku et al 160 proposed a low power dual gate TFT utilizing parylene film as gate electrode. It showed better switching characteristics and improved charge carrier density as compared to single gate device.…”