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

Abstract

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 (CaTiO3 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 CaTiO3 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.

A Review on Solution-Processed Organic Phototransistors and Their Recent Developments

“…There are some strategies to increase the C i Equation (3). One of them is using high-k (ε r ) dielectric materials to induce more charges [31,33,78,79]. The other one is to decrease the dielectric thickness (~d < 20 nm).…”

A Review on Solution-Processed Organic Phototransistors and Their Recent Developments

“…There are some strategies to increase the Ci (Equation 5). One of them is using high-k (εr) dielectric materials to induce more charges [31,33,78,79]. The other one is to decrease the dielectric thickness ( ~ d<20 nm).…”

“…A careful combination of organic solvents and NP-to-polymer volume ratio can be sufficient enough to rule out any required surface modification [81]. Inorganicorganic bilayer is another way to make a hybrid dielectric, for instance PMMA/ Ta2O5 [78].Chen et al reported development of [79] low-power OFETs with solution-processable nanocomposite of PVP and calcium titanate nanoparticles (CaTiO3 NPs, k≈150) as the gate dielectric. For a p-type OFET, high work function metals, such as Au, Pt are chosen as the S/D electrodes.…”

ZnO Nano-Particles Production Intensification by Means of a Spinning Disk Reactor

“…Nowadays, nanoparticle production has increased in a notable way due to its widespread number of applications in different sectors—such as electronic and energy storage [ 1 , 2 , 3 , 4 ], industrial catalysis [ 5 , 6 ], pharmaceutical and biomedical [ 3 , 7 , 8 , 9 ], food [ 10 , 11 , 12 ], civil and waste re-use [ 13 , 14 , 15 , 16 ], and the environment [ 13 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. The production of nanoparticles requires particular operating conditions and equipment, in particular the achievement of micro-mixing conditions [ 24 , 25 ] to avoid rapid aggregation phenomena [ 26 , 27 ], or the use of complexing agents to reduce surface electrostatic attraction among nanoparticles, such as carboxy-methyl-cellulose, alginate, xanthan and other organic compounds [ 28 , 29 ].…”