Anisotropic dielectric function spectra from single-crystal CuInSe2 with orientation domains

The anisotropic optical constants of slightly In-rich CuInSe2 are determined on the (112) surface of a naturally grown single-crystal sample with orientation domains using generalized spectroscopic ellipsometry for photon energies between 0.8 and 4.5 eV. Orientation domains within the sample, revealed by electron diffraction investigation, cause biaxial response of the sample surface. The CuInSe2 dielectric functions are extracted at each wavelength rigorously considering orientation domains and surface roughness effects, and improve previous results. (C) 2001 American Institute of Physics.