(142b) Tailoring Dissolution for Phothermal Patterning of Semiconducting Polymers

The industrial advancement of semiconducting polymers (SPs) encounters a significant challenge due to the absence of an inexpensive, rapid, and viable patterning technology capable of producing sub-micron features. Our study dives into photothermal patterning (PPL) and its potential to address this challenge by enabling the precise tuning of the temperature at which a polymer dissolves, facilitating pattern formation. PPL operates on the principle of polymer dissolution: a thin film is submerged in a binary solvent mixture containing both a good and a bad solvent for the polymer at a specific ratio which can be tuned for instance 1-2, Dichlorobenzene (DCB) and Cyclohexanone (CHN). At room temperature, the polymer remains insoluble; however, upon exposure to a laser, the polymer undergoes a non-emissive process, heating up the surrounding solvent and inducing dissolution of the film, thus creating patterns. The selection of the solvent mixture ratio allows for the customization of the dissolution temperature of the polymer. In this study, we experimentally explored the dissolution temperature of poly(3-hexylthiophene) (P3HT) using various combinations of solvents, demonstrating the tunable control over dissolution. Furthermore, we investigated how controlling the molecular weight and polydispersity index (PDI) of the polymer impacts both the dissolution range and the quality of the patterns produced. Overall, our method, coupled with the associated theoretical model, lays the groundwork for the development of a cost-effective and rapid photo-patterning technology for SPs. This advancement opens up new avenues for industrial applications in the micro-fabrication of organic electronic devices.