Prolonged mechanical dynamics via imide bridged ZnO composites for fast response flexible photo-electronics

Abstract

In this study, we incorporate a promising small molecule—n-type perylene diimide derivative (NPDI)—into widely used ZnO nanoparticles (NPs) as the electron transport layer, which effectively controls interface defects and leads to significant improvements in the performance and mechanical durability of organic optoelectronic devices. Conventional ZnO NP systems suffer from defects caused by oxygen vacancies at the interface with the Ag electrode in a single-layer configuration, which hinder charge transport and mechanical stress resistance. When the ZnO/NPDI bilayer is introduced, the defects in ZnO are smoothed and bonded, forming a durable passivation layer that inhibits charge recombination and enhances the mechanical properties of flexible devices. Moreover, the ZnO/NPDI bilayer forms an ohmic contact with the Ag electrode while simultaneously enhancing the hole injection barrier, facilitating smooth charge transport and effective dark current suppression. Accordingly, ZnO/NPDI-based flexible organic devices exhibit reduced internal resistance and enhanced stability under bending stresses due to successful interface optimization.