Top gate copper phthalocyanine thin film transistors with laser-printed dielectric

摘要

Dielectric layers involved in top gate organic thin film transistors (TG-OTFTs) have been fabricated by using laser induced forward transfer (LIFT) technique. Poly(methyl methacrylate) (PMMA) as insulating polymer was spin-coated on a quartz substrate and transferred by laser on an acceptor substrate to form a dielectric layer on top of an organic semiconducting layer and source/drain contacts both previously vapour phase deposited. Copper phthalocyanine (CuPc) has been chosen to form p-type organic active layers. The nature of transferred patterns and the efficiency of LIFT confirm the important potential of a laser printing technique in the development of plastic microelectronics. Electrical characterizations in TG configuration demonstrated that transistors are fully operative with hole mobility up to 8.6 × 10~(-3) cm~2/Vs. A comparative study with others dielectric layers in bottom gate transistors (BG-OTFTs), as PMMA spin-coated and silicon dioxide SiO_2, points out more precisely the limiting parameters to an efficient charge transport in the conducting channel created at the interface between PMMA and CuPc.