Near-infrared absorption of π-stacking columns composed of trioxotriangulene neutral radicals

Abstract

Organic electronics: strong near-infrared light absorption with radical columns Near-infrared light absorption is enhanced by trioxotriangulene radicals that self-assemble into one-dimensional columns. Organic materials are attractive candidates for solar cells as they are inexpensive and have strong light absorption at visible wavelengths. This usually does not extend into the near-infrared region, however, restricting their use in this technologically-important wavelength range. A team of researchers in Japan led by Yasushi Morita from Aichi Institute of Technology and Hiromi Nakai from Waseda University show that crystals of trioxotriangulene can have unusually strong near-infrared absorption. With the aid of large-scale quantum chemistry calculations, they show that the key to this property is the tendency of their trioxotriangulene derivatives to stack into one-dimensional columns, which led to an overlap of electronic orbitals from different molecules.