Optical properties and electronic energy-band structure of Cu2ZnSnS4.

Optical properties of the quaternary Cu2ZnSnS4 semiconductor have been studied by optical absorption, photoluminescence, photoreflectance, and thermoreflectance measurements. Optical absorption measurements suggest that Cu2ZnSnS4 is a direct-gap semiconductor having the band gap of ∼1.46 eV at 11 K. The photoreflectance and thermoreflectance spectra reveal distinct structures at energies of the critical points in the Brillouin zone. By performing the band-structure calculation, these critical points are successfully assigned to specific points in the Brillouin zone. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]