Low-Power Flexible Organic Field-Effect Transistors with Solution-Processable Polymer-Ceramic Nanoparticle Composite Dielectrics

• Published in: Nanomaterials (Basel, Switzerland) Switzerland), 2020-03, Vol.10 (3), p.518
• Main Authors: Chen, Xiong, Zhang, Hao, Zhang, Yu, Guan, Xiangfeng, Zhang, Zitong, Chen, Dagui
• Format: Article
• Language: English
• Subjects: calcium titanate nanoparticles; dielectric; organic field effect transistors (ofets); solution-process
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano10030518

Polymer-ceramic dielectric composites have been of great interest because they combine the processability of polymers with the desired dielectric properties of the ceramics. We fabricated a low voltage-operated flexible organic field-effect transistor (OFET) based on crosslinked poly (4-vinyl phenol) (PVP) polymer blended with novel ceramic calcium titanate nanoparticles (CaTiO NPs) as gate dielectric. To reduce interface roughness caused by nanoparticles, it was further coated with a very thin PVP film. The resulting OFET exhibited much lower operated voltage (reducing from -10.5 V to -2.9 V), a relatively steeper threshold slope (~0.8 V/dec) than those containing a pure PVP dielectric. This is ascribed to the high capacitance of the CaTiO NP-filled PVP insulator, and its smoother and hydrophobic dielectric surface proved by atomic force microscopy (AFM) and a water contact angle test. We also evaluated the transistor properties in a compressed state. The corresponding device had no significant degradation in performance when bending at various diameters. In particular, it operated well continuously for 120 hours during a constant bending stress. We believe that this technology will be instrumental in the development of future flexible and printed electronic applications.