Intrinsically Stretchable Organic Solar Cells without Cracks under 40% Strain

Abstract

Intrinsically stretchable organic solar cells (IS‐OSCs) have been recently spotlighted for their omnidirectional stretchability, seamless integrability to any surface, and facile fabrication. Due to these attributes, IS‐OSCs are ideal off‐grid power sources, especially for wearable electronics in real‐life. However, under human body elongation as high as ≈40%, cracks in IS‐OSCs are considered inevitable, and the origin of the mechanical failure is rarely identified. Herein, the crack‐initiation and the propagation mechanism are first clarified. Based on this, a crack‐free substrate/transparent electrode platform for stretchable electronics is also suggested. A double‐locking scheme, which reinforces the physical/chemical adsorption within the most mechanically fragile layer, a poly(3,4‐ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and also with thermoplastic polyurethane substrate, is introduced. As a result, the crack‐onset strain of double‐locked IS‐OSCs surpasses 40%, while that of pristine ones is less than 20%. The IS‐OSCs with the double‐locked system exhibits an efficient power conversion efficiency of 10.2%, and the absence of cracks allows the IS‐OSCs to maintain 79.7% of the initial PCE at 40% strain.

Recent advances in the construction and application of stretchable PEDOT smart electronic membranes

“…Lee et al 222 prepared crack-free IS-OSCs by spin-coating PEDOT:PSS on a 40% prestrained plasma-treated TPU substrate, in which PEDOT:PSS was doped with GOPS to enhance the physical/chemical interaction of the spin-coating with the TPU substrate. The as-prepared IS-OSCs exhibited a power conversion efficiency (PCE) of 10.2%, maintained 79.7% of the initial PCE at 44% strain, and 90% of the initial efficiency after 1000 cycles at 10% strain.…”

Nature-Inspired Semiconducting Polymers with Peptide Conjugation Breakers for Intrinsically Stretchable and Self-Healable Transistors

“…For instance, elastomers like polydimethylsiloxane (PDMS) and styrene–ethylene/butylene–styrene (SEBS), alongside covalent cross-linkers − with flexible additives, have proven to reduce long-range crystallinity. Furthermore, stacking OSCs with interfacial supporting layers, such as polyurethane and PDMS, has shown promise in delaying crack formation and propagation. However, these strategies have inherent limitations, including complex manufacturing processes associated with geometry engineering, reduced electrical properties due to inhomogeneous mixing in additive engineering, and low crack onset strain within interfacial engineering.…”