Twisted terrylene dyes: synthesis and application in organic solar cells

Two twisted terrylene diimides (TDIs), namely TDI2 and BTDI3, have been designed and synthesized. In comparison to monomeric TDI, their molecular geometries and optoelectronic properties have been systematically investigated. BTDI3, with a highly twisted 3D geometry, shows the best light-absorbing capability in the range of 500-700 nm and a suitable LUMO level. Simultaneously, a preliminary exploration of their photovoltaic performances was carried out. The optimized device based on PBDT-TS1/BTDI3 produces a power conversion efficiency (PCE) of 3.64%, demonstrating the potential of terrylene dyes in the photovoltaics field.