Efficient and robust intrinsically stretchable organic solar cells via mechanically interlocked oligomer integration†

Intrinsically stretchable organic solar cells (IS-OSCs) offer promising solutions for powering wearable electronics and skin-integrated sensors, yet reconciling mechanical durability with high efficiency remains a fundamental challenge. Here, we propose, for the first time, integrating a mechanically interlocked oligo[2]rotaxane into an all-polymer PTzBI-oF:PY-IT blend. The oligomer's sliding crown ether macrocycles form electrostatic interactions with both donor and acceptor π-backbones and enable mobility along the axial chain under strain. These unique features facilitate molecular-level stress dissipation while preserving the fibrillar network critical for charge transport. At the optimal loading, the ternary blend exhibits a significantly increased fracture strain of 17.8% and a crack-onset strain of 30%, while retaining a rigid device power conversion efficiency (PCE) of 14.88%. The corresponding IS-OSCs retain 80% of their initial PCE under 34% tensile strain, establishing mechanically interlocked structures as a transformative strategy for developing high-performance and robust stretchable organic electronics.