An easily available near-infrared absorbing non-fullerene photovoltaic electron acceptor with indeno[1,2-b]indole as the central core

Abstract

Unsymmetric indeno[1,2-b]indole (IN) was demonstrated to be an easily available yet perspective building unit in constructing non-fullerene small molecular photovoltaic electron acceptor. An A-π-D-π-A compound using IN as the central electron-rich aromatic core, namely INTIC, was found to show intense and broad near-infrared (NIR) absorption in the range of 600–950 nm. Organic solar cells using INTIC as the acceptor material show a peak short circuit current over 15.3 mA cm−2, and a maximum power conversion efficiency (PCE) of 7.27%.