Locking the morphology with a green, fast and efficient physical cross-linking approach for organic electronic applications

Molecular packing and stability play crucial roles in determining the performance of organic electronic devices. To optimize the morphology of active layer, thus to improve the performance, especially the stability of devices, cross-linking technique is a viable approach that has been extensively applied to stabilize the morphology. In this work, we demonstrate a green, fast and efficient physical approach using hyperthermal hydrogen induced cross-linking (HHIC) to lock the morphology of organic electronic materials. By controlling the kinetic energy of the hyperthermal hydrogen (H₂) molecules, we can efficiently cleave the C-H bonds and induce cross-linking in a conjugated polymer. The cross-linking can be achieved in 1 min at room temperature, and the cross-linked films have excellent thermal stability and high resistance to organic solvents. Organic field effect transistors fabricated with HHIC treated poly (3-hexylthiophene) (P3HT) has comparable charge carrier mobility and superb stability than the untreated devices. Compared to the conventional chemically driven cross-linking approach, HHIC does not require additional modification in molecular structure, and the fast and non-destructive advantages have high potential for wide applications of highly stable organic electronic devices.