Organoboron donor-π-acceptor chromophores for small-molecule organic solar cells

We introduce the use of facilely synthesizable and low-bandgap boron chromophores as donors in planar heterojunction solar cells. We show that simple changes in the compositional properties of these molecules can improve the performance of the devices. A simultaneous grafting of NO2 acceptor and N(Et2) donor groups into the molecule core causes an increase in efficiency of almost 50%. Such enhanced efficiency is mainly due to a higher photocurrent. The origin of this phenomenon is investigated.