Optical characterization of band-edge property of In6S7 compound

The evaluation of band gap, exciton, and electronic structure of an energy compound is crucial and essential. We report direct optical evidence of band gap, band-edge exciton, and white-light photoelectric conversion for a solar-energy material In6S7 herein. The direct gap of In6S7 is determined to be 0.93 eV. The value is extremely suitable for absorption of full sunlight spectrum extension to near infrared region. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3698334]