Long‐Term‐Stable Strong Second Harmonic Generation in Flexible DAST−PVDF Composite Films Realized by the Interface Interactions (Adv. Mater. Interfaces 17/2021)

DAST–PVDF Composite Films In article number 2100485, Xiaomeng Cheng, Xiangdong Xu, and co‐workers demonstrate that the interface interactions of the electrostatic interactions and the intermolecular hydrogen bonds between 4‐N,N‐dimethylamino‐4′‐N′‐methyl‐stilbazolium tosylate (DAST) and polyvinylidene fluoride (PVDF) improve the conjugation of p electrons and molecular ordering of DAST, thus making tunable and long‐term‐stable strong nonlinear optical properties of flexible composite films.