Siloxane Side Chains: A Universal Tool for Practical Applications of Organic Field-Effect Transistors

Abstract

To systematically address the intriguing question of how siloxane termini of the side chains relative to alkylterminal groups affect the various inherent properties of conjugated polymersincluding optical, electrical, and morphological characteristicswe have synthesized model polymers (PDPPTT-R TG and PDPPTT-Si TG , together with an accompanying reference PDPPTT-ref) containing an identical backbone yet possessing different terminal groups. In order to fairly compare the end functionalities by eliminating molecular weight (M n ) and polydispersity index (PDI) variations that may act as complicating factors, the polymers used in this study have been controlled to have similar M n and PDI by carefully optimizing the catalyst system and reaction conditions. Although the molecular packing and orientation behaviors of PDPPTT-R TG and PDPPTT-Si TG are very different from each other, both polymers exhibit very high mobility exceeding 4.5 cm 2 V −1 s −1 . More meaningfully, organic field-effect transistors (OFETs) based on PDPPTT-Si TG are highly stable over extended periods in humid environments. Our findings provide new insights into the molecular design strategy aimed at the simultaneous enhancement of charge-carrier mobility and ambient stability, which is of great importance for practical OFET applications.

The Effects of Side Chains on the Charge Mobilities and Functionalities of Semiconducting Conjugated Polymers beyond Solubilities

“…The siloxane chains were introduced to the DPP‐based conjugated polymers P149 – P152 . Bimodal interchain packing was also observed for P149 .…”

“…The siloxane chains were introduced to the DPP‐based conjugated polymers P149 – P152 . Bimodal interchain packing was also observed for P149 . In comparison, the reference polymer with the same backbone, to which branching alkyl chains with –(CH 2 ) 4 as the spacer are attached, shows the predominant edge‐on packing mode.…”

Recent Advances in the Bias Stress Stability of Organic Transistors

“…In particular, the reliability of OFETs under realistic atmospheric and electrical operating conditions has come under intense scrutiny as OFETs move closer to real‐world applications . Much research effort has been devoted to developing novel OSC materials with high μ FET values and superior chemical stability against atmospheric species and unintentional light exposure, and some studies have successfully demonstrated devices with high performance, much improved environmental stability, and enhanced shelf life in air …”

Mechanical, Thermal, and Electrical Properties of Flexible Polythiophene with Disiloxane Side Chains

“…Therefore, we synthesized a polythiophene with higher molecular weight and prepared self‐supported cast films, so that the desired mechanical properties were available. Owing to the introduction of disiloxane moiety, the dissolubility and processability of polymer are particularly improved and easily dissolved in organic solvent like hexane or tetrahydrofuran …”