Intrinsically stretchable polymer semiconductors are highly demanding for flexible electronics. However, it still remains challenging to achieve synergy between intrinsic stretchability and charge transport property properly for polymer semiconductors. In this paper, terpolymers are reported as intrinsically stretchable polymeric semiconductors with good ductility and high charge mobility simultaneously by incorporation of non‐centrosymmetric spiro[cycloalkane‐1,9′‐fluorene] (spiro‐fluorene) units into the backbone of diketopyrrolopyrrole (DPP) based conjugated polymers. The results reveal that these terpolymers show obviously high crack onset strains and their tensile moduli are remarkably reduced, by comparing with the parent DPP‐based conjugated polymer without spiro‐fluorene units. They exhibit simultaneously high charge mobilities (>1.0 cm2 V−1 s−1) at 100% strain and even after repeated stretching and releasing cycles for 500 times under 50% strain. The terpolymer P2, in which cyclopropane is linked to the spiro‐fluorene unit, is among the best reported intrinsically stretchable polymer semiconductors with record mobility up to 3.1 cm2 V−1 s−1 at even 150% strain and 1.4 cm2 V−1 s−1 after repeated stretching and releasing cycles for 1000 times.

Molecular systems that can function as photoresists are essential for the fabrication of flexible electronics through all‐photolithographic processes. Most of the reported molecular systems for photo‐patterning of polymeric semiconductors contain binary or multi‐components. In comparison, single component semiconducting photoresist is advantageous since it will circumvent the optimization of phase separation and ensure the patterned semiconducting thin films to be more uniform. In this paper, a single component semiconducting photoresist (PDPP4T‐N3) by incorporating azide groups into the branching alkyl chains of a diketopyrrolopyrrole‐based conjugated polymer is reported. The results reveal that i) the azide groups make the side chains to be photo‐cross‐linkable; ii) uniform patterns with size as small as 5 µm form under mild UV irradiation (365 nm, 85 mW cm−2) at ambient conditions; iii) such photo‐induced cross‐linking does not affect the inter‐chain packing; iv) benefiting from the single component feature, field‐effect transistors (FETs) with the individual patterned thin films display satisfactorily uniform performances with average charge mobility of 0.61 ± 0.10 cm2 V–1 s–1 and threshold voltage of 3.49 ± 1.43 V. These results offer a simple yet effective design strategy for high‐performance single component semiconducting photoresists, which hold great potentials for flexible electronics processed by all‐photolithography.