P vdf trfe

For Fe-OFET fabrication, highly doped n-type (100) silicon wafers with 50 nm SiO₂ layers were first cleaned in an ultrasonic bath in a succession of acetone and 2-propanol for 10 min each. Bottom gate electrodes were formed through thermal evaporation of Ti (3 nm) and Au (20 nm) at a deposition speed of ~0.1 Å/s. P(VDF-TrFE) (Solvay, Inc.) was dissolved in 2-butanone with 3 wt.% concentration. The P(VDF-TrFE) solution was spin-coated onto the Si/SiO₂ substrate, which was then soft-baked at 90°C for 30 min. The substrate was exposed to an annealing process in a vacuum chamber at 120°C for 2 h. For the buffering process, PMMA (Sigma-Aldrich MW = 996 k) was dissolved in anisole (Sigma-Aldrich) with a concentration of 0.1 wt.%. The solution was spin-coated onto the P(VDF-TrFE) film, followed by soft backing at 90°C for 10 min. C₈-BTBT was thermally evaporated at a speed of ~0.1 Å/s to obtain 30 nm-thick semiconducting films. Finally, MoO₃ (3 nm) and Au (35 nm) were successively evaporated under the same conditions to form the source and drain electrodes. And the channel width and length were 1000 μm and 200 μm, respectively.

PVDF–TrFE (70:30) was obtained from Solvay (Brussels, Belgium). P25^®-TiO₂ nanoparticles was kindly supplied by EVONIK (Essen, Germany). MB and N,N-dimethylformamide (DMF) 99% were supplied by Merck. CIP 98% and IBP 98% were obtained from Sigma-Aldrich (Darmstadt, Germany). NaOH 97% was obtained from VWR (Radnor, PA, USA). Milli-Q ultrapure water was used in all experiments.

The PVDF-TrFE (70-30 mol %, MW = 300 kDa) copolymer was purchased from Solvay in powder form. Boron Nitride Nanotubes (BNNT) were obtained from BNNT Ltd. PVDF-TrFE was dissolved in a 1:1 ratio DMF/acetone mixture with a solute ratio of 5:1, and cast onto a glass plate to form films of 20–30 um thickness. BNNTs were subjected to ultrasonication for 4 h in a 1:1 ratio DMF/acetone mixture before the addition of PVDF-TrFE. Solution of PVDF-TrFE were subjected to varying drying temperatures as described below. After solvent evaporation, the films were further subjected to a subsequent 12 h of further annealing at the drying temperature.