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

• Main Authors: Dongkyu Kim, Choongik Kim
• Format: Article
• Language: English
• Published: MDPI AG 2018-07-01
• Series: Coatings
• Subjects: organic thin-film transistors; dielectric; organosilicate; copolymer
• Online Access: http://www.mdpi.com/2079-6412/8/7/236

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 cm2·V−1·s−1 and an Ion/Ioff of >105. Furthermore, dielectric films were used for the fabrication of TFTs on flexible substrates.