Magnesium diethynylporphyrin derivatives with strong near-infrared absorption for solution-process bulk heterojunction organic solar cells

Abstract

Magnesium diethynylporphyrin derivatives with strong near-infrared absorption were obtained. These derivatives possess electron rich units directly introduced to the porphyrin core. The electron rich units caused strong absorption on the near-infrared region due to an intramolecular charge transfer. Theoretical calculation also proved that the derivatives showed large oscillator strength at the Q band. As a donor material, such large absorption coefficient in the range of long wavelength region is a desirable characteristic for organic solar cells. Organic photovoltaic devices using these diethynylporphyrin derivatives gave a PCE of 2.91% in optimal conditions.