Fabrication and electrical characteristics of organic thin film transistor using π-conjugated dendrimer

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 313-314; pp. 431 - 434
• Main Authors: Cho, Mi Yeon, Kang, Han Saem, Kim, Kihyun, Kim, Su Jin, Joo, Jinsoo, Kim, Kyung Hwan, Cho, Min Ju, Choi, Dong Hoon
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2008; Elsevier
• Subjects: Chemistry; Colloidal state and disperse state; Dendrimer; Exact sciences and technology; General and physical chemistry; Mobility; Organic thin film transistor; Surface physical chemistry; Mobility; Dendrimer; Organic thin film transistor; Branched polymer; Nanotechnology; Dendritic structure; Electrical characteristic; Thin film
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2007.05.063

We fabricated organic thin film transistors (OTFTs) by using soluble π-conjugated dendrimers of 4(HPBT)-benzene, 4(HPTT)-benzene, and 4(HPDTT)-benzene. Electrical characteristics such as current–voltage characteristic curves and their temperature dependence were measured for the dendrimer-based OTFT devices. The active layer using planar π-conjugated dendrimers was spin-coated, and thermally grown silicon dioxide layer was used as a dielectric layer. Through the measurements of source–drain currents with varying gate voltages, we obtained charge carrier mobility (μ), on/off current ratio (Ion/off), and threshold voltage (Vth). The 4(HPBT)-benzene and 4(HPTT)-benzene-based OTFT devices showed that the μ's were ∼6.2×10−3cm2/Vs and ∼1.9×10−3cm2/Vs, respectively. We measured temperature-dependent mobility and activation energy (Ea) of the dendrimer-based OTFTs by using Arrhenius fitting. The Ea's of 4(HPTT)-benzene and 4(HPDTT)-benzene-based OTFTs were estimated to be ∼0.39eV and ∼0.13eV, respectively. In case of 4(HPBT)-benzene-based OTFT, two trap levels were measured and the Ea's were estimated to be ∼0.027eV and ∼0.22eV.