A highly porous and conductive composite gate electrode for OTFT sensors

Abstract

A porous and conductive gate electrode of PEDOT:PSS and sulphonated mesoporous silica nanoparticles is investigated for organic thin film transistor sensors.

Effect of Gate Conductance on Hygroscopic Insulator Organic Field‐Effect Transistors

“…From Figure 3a and 3b, the HIFET with a gate electrode of 100% PEDOT:PSS dispersion exhibited excellent output and transfer characteristics, comparable to similar PEDOT:PSS gated devices previously reported. [11,21] The 100% PEDOT:PSS gated HIFET exhibited a well-defined saturation regime, distinct current modulations, and relatively low OFF currents. In common with previous reports, our HIFETs operate under low voltages.…”

“…Our HIFET device employs a top gate/bottom contact architecture (Figure 1a, b), with poly(3hexylthiophene-2,5-diyl) (P3HT) as the semiconductor and poly(4-vinylphenol) (PVP) as the hygroscopic dielectric, closely following previous reports. [5,11,16,21] The HIFETs have a channel length of 50 μm and width of 3 mm and were fabricated using solution processing methods (details in experimental section) on pre-patterned indium tin oxide (ITO) source and drain electrodes, with a separate gate contact pad. Typical output characteristics of a modified HIFET using SO3H-Si-MCM-41 as the gate for proton sensitivity are shown in Figure 1c.…”

“…Though the output characteristics have defined linear and saturations regimes, the device exhibits poorer saturation current, lower ON current and higher OFF current than a HIFET with a PEDOT:PSS gate (Figure 1d), which has a much higher conductance. [21] This suggests a strong influence of gate electrode conductance on transistor characteristics.…”

“…[20] Recently, we demonstrated that, for our proton sensitive HIFET gated with a film of proton conducting sulfonated mesoporous silica nanoparticles (SO3H-Si-MCM-41), the transistor characteristics are significantly improved by adding conductive polymer poly (3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS), while maintaining proton sensitivity. [21] This suggests a strong relationship between transistor performance and gate conductance for HIFETs. In this report, we have systematically studied and established the effect of the conductance of the gate electrode on key figures of merit for HIFETs, using PEDOT:PSS as the model gate electrode.…”

The effect of air exposure on device performance of flexible C8-BTBT organic thin-film transistors with hygroscopic insulators

“…On the other hand, even weak dopants can improve the device performance [43]. It is considered that the protons diffuse into the hygroscopic dielectric layer, resulting in doping of the semiconducting channel and increase of I ds [44][45][46] .…”