Enhancing Stability of Organic Field-Effect Transistors with Thermally Cleavable Side Chains

Organic electronics have emerged as a promising field due to their solution processability, structural tunability, and potential for flexible, wearable devices. While much research has focused on improving electronic performance, the stability and durability of organic devices remain critical challenges. This study introduces the incorporation of thermally cleavable side chains to enhance the thermal stability of donor-acceptor (DA) conjugated polymers i.e. PFFBT4T based organic transistors. We systematically investigated the impact of tertiary ester side chain cleavage on thermal stability of PFFBT4T based polymers using spectroscopic ellipsometry and UV-Vis spectroscopy, with measurements taken both below and above the glass transition temperature (T_g). Thermal studies revealed that T_g increased by approximately 70 °C after removing the low T_g cleavable side chains. X-ray scattering confirmed the preservation of crystalline domains post-cleavage. Furthermore, a temperature-dependent analysis of transistor performance showed that the cleaved PFFBT4T polymers-maintained stability up to 200 °C, unlike the control polymer. This enhanced stability is attributed to the increased T_g, and retention of crystalline morphology after cleavage.