Photo-Patternable and Healable Polymer Semiconductor Enabled by Dynamic Covalent Disulfide Bonding

Abstract

Apart from charge transport property, polymer semiconductors with patternable and healable functions are highly demanding for the fabrication of organic circuits. Herein, by leveraging the dynamic covalent disulfide bonding of thioctic acid (TA) groups, we successfully integrate photo-patterning and thermal-healing capabilities into a single diketopyrrolopyrrole (DPP)-based polymer semiconductor for the first time. The results show that the thin film of DPP-based conjugated donor-acceptor polymer with TA groups in the side chains exhibits excellent photo-patterning capability under 365 nm UV light irradiation, with sensitivity (S) of 210 mJ⋅cm⁻² and contrast (γ) of 1.2. Importantly, the patterning process has minimal impact on thin film morphology, interchain stacking, and charge transport mobility. Moreover, the patterned thin films, which were initially scratched, can be well healed after exposure to chloroform vapor and further thermal annealing, and simultaneously the charge mobility can be restored. In comparison, the scratched thin film of PDPP4T without TA groups in the side chains achieves only 82.6 % recovery of scratch depth and 54.5 % recovery of charge mobility under the same conditions. These results demonstrate the feasibility of constructing multifunctional polymer semiconductors by incorporating TA groups in the side chains, offering a new pathway to lithography-compatible, self-healing smart flexible devices.