Organic Field‐Effect Transistors Based on Ternary Blends Including a Fluorinated Polymer for Achieving Enhanced Device Stability

Abstract

The stability of organic semiconductors (OSCs) is strongly hampered by the presence of water molecules. One approach that has been proved to lead to organic field‐effect transistors with an enhanced performance is the use of blends of OSCs with insulating binding polymers. In this work, the fabrication of OSC thin films based on polymeric ternary blends including a hydrophobic fluorinated polymer is reported as a novel route to engineer long‐term reliable organic field‐effect transistors (OFET) devices. In particular, OFETs based on blends of bis(triisopropylsilylethynyl)pentacene (TIPS) with polystyrene (PS) and poly(pentafluorostyrene) (PFS) are explored. The PS:PFS ratio is tuned in order to find the optimum formulation. It is shown that films including 20% of PFS in the polymeric blend exhibit an improved device performance, which is reflected by a low bias stress and an exceptional environmental stability, without significantly hampering the OFET mobility. This work advocates that adding a small percentage of fluorinated polymers in OSC blends is a promising route to realize more reliable and stable devices without importantly compromising the device mobility.

X‐ray Detectors With Ultrahigh Sensitivity Employing High Performance Transistors Based on a Fully Organic Small Molecule Semiconductor/Polymer Blend Active Layer

“…OFETs based on the parent compound TIPS‐pentacene fabricated following the same methodology (i.e., blended with PS and deposited by BAMS, hereafter TIPS:PS) led to device mobilities in the range 0.5‐1 cm 2 V –1 s –1 and a density of traps of (9.2 ± 2.8) 10 11 eV –1 cm –2 . [ 13,16,26,49 ] In comparison, TMTES films show a field‐effect mobility between two and four times higher, that we ascribe to the more favorable 2D herringbone crystal packing and also to the lower presence of interfacial hole‐traps.…”

Binder polymer influence on the electrical and UV response of organic field-effect transistors

“…Comparing the position of the first (001) peak, small shifts can be distinguished, which might be indicative of some lattice strain caused by the different binding polymers. 45,46 The OSC thin films were investigated as active layer in OFETs, in a bottom gate bottom contact structure, with the aim at exploring how the binder polymer affects their electrical performance (see Figure 3a for the device configuration). The transfer characteristics for all the devices in the saturation regime are shown in Figure 3b-e (see Figure S4 for the output characteristics), and the parameters extracted are collected in Table 1.…”

Vertical Phase Separation Structure for High‐Performance Organic Thin‐Film Transistors: Mechanism, Optimization Strategy, and Large‐Area Fabrication toward Flexible and Stretchable Electronics

“…High-uniformity and high-qualitycrystalline film led to fieldindependent mobility with low dispersion. In 2022, Tamayo et al [113] found that addition of poly(pentafluorostyrene)(PFS) in blends of small molecules/insulator polymer is an effective strategy to improve the long-term reliability of OTFTs. Ultrahigh hydrophobicity of PFS acted as barrier against humidity, which reduced charge traps and deterioration of the crystalline films.…”