Effects of volatile additives in solutions used to prepare polythiophene-based thin-film transistors

Abstract

We investigate the effects of volatile additives in solutions used to prepare thin-film transistors (TFTs) of regioregular poly(3-hexylthiophene) (P3HT). We use the additives trifluoromethylbenzene (TFMB) and methylcyclohexane (MCH) because they are poor solvents for P3HT. The additives improve the performance of the resulting TFTs when the boiling point (T b ) of the major solvent, carbon tetrachloride, is lower than that of the additive. The maximum mobility is (4.0 6 0.9) Â 10 -2 cm 2 V -1 s -1 , which is 6.1 times larger than that of TFTs prepared without TFMB or MCH added to the solution; the on/off ratio and the subthreshold slope were also improved. The relative T b of the solvent and the additive affected the film formation with the amount of TFMB or MCH remaining at the final stage of thin film deposition influencing the precipitation of P3HT aggregates.

Solvent Additives: Key Morphology‐Directing Agents for Solution‐Processed Organic Solar Cells

“…However, enhancement only occurs for deposition solvents with lower boiling points than TFMB, such as carbon tetrachloride (CCl 4 ), CF, and THF. This effect is not due to doping interactions, as similar improvement was observed for methylcyclohexane, a poor solvent with similar vapor pressure to TFMB but different electronic structure . Later work found that additives with good solubility for the active layer, such as trichlorobenzene, enhance performance, suggesting that low vapor pressure is also a factor .…”

Fluorinated Alcohol-Processed N-Type Organic Electrochemical Transistor with High Performance and Enhanced Stability

“…Especially, the ion–electron coupling is sensitive to very small changes in film morphology, which is caused by the penetration of water coupled with dopant ions into the films, even though tuning the film morphology and microstructure to enhance the electronic mobility and volumetric capacitance of the polymeric semiconductors by backbone or side-chain engineering and processing conditions has been established in OECTs. , Less progress has been made in the efficient preparation of optimal nanostructures using state-of-the-art n-type small-molecule semiconductors. Apparently, the morphology can be modified by the molecular structure of the active layer. − In addition, it is also evident that the processing conditions, including the selection of the solvents, additives, and posttreatment, are also very important prerequisites to the film microstructure. − The choice of the semiconductor–solvent system in the film preparation process is of utmost importance, which can provide fine control over the microstructure of the active layer during solution evaporation.…”

Synthesis and Phase Behavior of a New Thiophene Monomer as Nematic Liquid Crystal

“…Today, the thiophene derivatives occupy an important position in the study of the organic conjugated materials. Functionalized thiophenes based molecules are being shown to be the potential candidates for high end applications [10] [11]. From a scientific and industrial point of view, the liquid crystalline (LC) thiophene derivatives are fascinating because they combine the electrical properties of thiophene with the optical properties of conventional LC materials.…”