2022 article

Achieving 19% Power Conversion Efficiency in Planar-Mixed Heterojunction Organic Solar Cells Using a Pseudosymmetric Electron Acceptor

Gao, W., Qi, F., Peng, Z., Lin, F. R., Jiang, K., Zhong, C., … Jen, A. K.-Y. (2022, July 11). ADVANCED MATERIALS.

By: W. Gao*, F. Qi*, Z. Peng n, F. Lin*, K. Jiang*, C. Zhong*, W. Kaminsky*, Z. Guan* ...

co-author countries: China 🇨🇳 Hong Kong 🇭🇰 United States of America 🇺🇸
author keywords: electron acceptors; free charge generation; organic solar cells; planar-mixed heterojunctions; pseudosymmetry
Source: Web Of Science
Added: July 26, 2022

A record power conversion efficiency (PCE) of over 19% is realized in planar-mixed heterojunction (PMHJ) organic solar cells (OSCs) by adopting the asymmetric selenium substitution strategy in making a pseudosymmetric electron acceptor, BS3TSe-4F. The combined molecular asymmetry with more polarizable selenium substitution increases the dielectric constant of the D18/BS3TSe-4F blend, helping lower the exciton binding energy. On the other hand, dimer packing in BS3TSe-4F is facilitated to enable free charge generation, helping more efficient exciton dissociation and lowering the radiative recombination loss (ΔE2 ) of OSCs. As a result, PMHJ OSCs based on D18/BS3TSe-4F achieve a PCE of 18.48%. By incorporating another mid-bandgap acceptor Y6-O into D18/BS3TSe-4F to form a ternary PMHJ, a higher open-circuit voltage (VOC ) can be achieved to realize an impressive PCE of 19.03%. The findings of using pseudosymmetric electron acceptors in enhancing device efficiency provides an effective way to develop highly efficient acceptor materials for OSCs.