1,2,4-Triazoline-3,5-dione substituted perylene diimides as near infrared acceptors for bulk heterojunction organic solar cells

A series of perylene diimide derivatives (PDIs) with near infrared (NIR) absorption and different geometries were synthesized by introducing 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) and 4-butyl-1,2,4-triazoline-3,5-dione (BuTAD) to the bay position of PDIs through the Diels-Alder reaction. The compounds with various twisted three-dimensional (3D) structures were obtained through combining different connection units, and their aggregation and domain size of the donor-acceptor blends were adjusted. All of these compounds exhibit broad absorption in the range of 300-860 nm, high thermal stability (with a decomposition temperature over 350 degrees C), applicable lowest unoccupied molecular orbital energy levels (-3.70 similar to -3.74 eV), and appropriate solubility. Blending with a PM6 polymer donor, bulk heterojunction organic solar cells (BHJ OSCs) based on BDT-SBu-TADPDI(2) exhibited the highest power conversion efficiency of 2.74%. Their carrier mobility and morphology were investigated by Space-charge-limited current (SCLC) measurements and Atomic Force Microscopy (AFM) measurements respectively. This study provides a promising strategy to construct potential PDI-based acceptors with NIR absorption.

Automated summary

A series of perylene diimide derivatives with near infrared absorption and different geometries were synthesized by introducing PTAD and BuTAD. These compounds exhibit broad absorption, high thermal stability, and appropriate solubility, and can be used to construct organic solar cells with high power conversion efficiency when blended with PM6 polymer donor.