Air-Processable Silane-Coupled Polymers to Modify a Dielectric for Solution-Processed Organic Semiconductors

作者：Jang Mi; Yu Young Chang; Jeon Hyeonyeol; Youk Ji Ho^*; Yang Hoichang

来源：ACS Applied Materials & Interfaces, 2015, 7(9): 5274-5280.

DOI：10.1021/am508573q

• silane polymer
• polymer grafting
• solution-processable semiconductor
• poly(3-hexyl thiophene)
• organic
• field-effect transistor

Poly(styrene-r-3-methacryloxypropyltrimethoxysilane) (PSMPTS) copolymers were synthesized by the free radical polymerization of styrene and 3-methacryloxypropyltrimethoxysilane (MPTS) for use as surface modifiers. PSMPTS copolymers were spun-cast onto a hydrophilic SiO2 layer and were then annealed at 150 degrees C in ambient air. The polystyrene (PS)-based copolymer, with a molecular weight of 32 700 g mol(-1) and approximately 30 MPTS coupling sites, was easily grafted onto the SiO2 surface after annealing periods longer than 1 min, yielding a physicochemically stable layer. On the untreated and polymer-treated dielectrics, spin-casting of an ultrasonicated poly(3-hexyl thiophene) (P3HT) solution yielded highly interconnected crystal nanofibrils of P3HT. The resulting organic field-effect transistors (OFETs) showed similar mobility values of 0.01-0.012 cm(2) V-1 s(-1) for all surfaces. However, the threshold voltage (V-th) drastically decreased from +13 (for bare SiO2) to 0 V by grafting the PSMPTS copolymers to the SiO2 surface. In particular, the interfacial charge traps that affect Vth were minimized by grafting the 11 mol % MPTS-loaded copolymer to the polar dielectric surface. We believe that this ambient-air-processable silane-coupled copolymer can be used as a solution-based surface modifier for continuous, large-scale OFET fabrication.

• 出版日期2015-3-11