Thermal Release Transfer of Organic Semiconducting Film for High-Performance Flexible Organic Electronics

Polymer semiconductors have exhibited their perspective in flexible, stretchable, and wearable electronics, where high-performance polymer semiconductors are always expected for high device performance. Various directional alignment techniques have been put forward to enhance device performance. However, not all these techniques are suitable on flexible substrates. Solution-based deposition also suffers the risk of interface degradation between semiconducting/dielectric layers and therefore the degradation of device performance. A film transfer technique is one of promising measures to solve these problems. We developed a simple and reliable thermal release transfer technique to transfer well-aligned and centimeter-scaled polymer semiconducting film from rigid to flexible substrates. A friction-transferred polytetrafluoroethylene template on silicon was used to guide the anisotropic crystallization of organic semiconducting film. The semiconducting film was transferred onto a flexible substrate via thermal release tape whose adhesion was modulated by proper annealing treatment. The flexible device based on such transferred and well-aligned semiconducting film presented the largest carrier mobility of 1.02 cm2 V–1 s–1 and the largest on/off ratio of 2.6 × 104 than the other control devices. Bending measurements further proved that such devices presented good endurance on both tensile strain and bending cycling. As an example, an extended-gate organic transistor was developed as a proximity sensor to perceive the approach of a charged object.