A Ladder-Type Organosilicate Copolymer Gate Dielectric Materials for Organic Thin-Film Transistors

Abstract

A ladder-type organosilicate copolymer based on trimethoxymethylsilane (MTMS) and 1,2-bis(triethoxysilyl)alkane (BTESn: n = 2-4) were synthesized for use as gate dielectrics in organic thin-film transistors (OTFTs). For the BTESn, the number of carbon chains (2-4) was varied to elucidate the relationship between the chemical structure of the monomer and the resulting dielectric properties. The developed copolymer films require a low curing temperature (≈150 • C) and exhibit good insulating properties (leakage current density of ≈10 −8 -10 −7 A·cm −2 at 1 MV·cm −1 ). Copolymer films were employed as dielectric materials for use in top-contact/bottom-gate organic thin-film transistors and the resulting devices exhibited decent electrical performance for both p-and n-channel organic semiconductors with mobility as high as 0.15 cm 2 ·V −1 ·s −1 and an I on /I off of >10 5 . Furthermore, dielectric films were used for the fabrication of TFTs on flexible substrates.

Recent progress in ladder-like polysilsesquioxane: synthesis and applications

“…82,83 Based on these advantages, researchers have employed LPSQ as an additive or filler in polymer resins to enhance mechanical properties [84][85][86][87] and impart specific functionalities. [88][89][90][91][92] LPSQ is currently under active investigation as a base material for use in applications where POSS has encountered challenges, such as in hard coatings with various functionalities, [93][94][95][96][97] gate dielectrics, 82,[98][99][100][101] battery separators, [102][103][104] ionic liquid gelators, 34,105,106 and gas separation membranes, [107][108][109] thereby broadening the range of applications of silsesquioxanes (Fig. 1c).…”

“…Kim's group aimed to use alkyl or oxygen-bridged LPSQ as a gate dielectric, synthesized through the copolymerization of methyltrimethoxysilane (MTMS) and 1,2-bis(triethoxysilyl)alkane (BTES n ; n = 2–4) 101 (Fig. 10c).…”

Role of the Alkylation Patterning in the Performance of OTFTs: The Case of Thiophene-Functionalized Triindoles

“…Regarding the architecture of the device, the focus has been placed on optimizing the interface between these semiconductors and the Si/SiO 2 substrate in a bottom-gate top-contact OTFT. In fact, the presence of a passivation coating or anchored groups in the interface can greatly influence the growth and features of a vacuum-deposited thin film [41][42][43][44][45]. Specifically, the SiO 2 surface has been either functionalized with octadecyltrichlorosilane (OTS) as an aliphatic self-assembled monolayer (SAM) or coated with polystyrene (PS) as an aromatic polymeric layer.…”