title: Spectral optical properties of Cu2ZnSnS4 thin film between 0.73 and 6.5 eV.
abstract: A polycrystalline Cu2ZnSnS4 thin film was deposited on fused quartz by co-evaporation. The selected thickness was ~100 nm to avoid artifacts in its optical properties caused by thicker as-grown films. The composition and phase of the film were checked with x-ray fluorescence, Raman shift spectroscopy, scanning transmission electron microscopy, and energy dispersive x-ray spectroscopy. An improved spectroscopic ellipsometry methodology with two-side measurement geometries was applied to extract the complex dielectric function ε = ε1 + iε2 of the Cu2ZnSnS4 thin film between 0.73 and 6.5 eV. Five critical points were observed, at 1.32 (fundamental band gap), 2.92, 3.92, 4.96, and 5.62 eV, respectively. The ε spectra are in reasonable agreement with those from theoretical calculations.
authors.affiliation: National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, USA. Jian2.Li@nrel.gov
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Hui
authors.initials: H
authors.lastname: Du
authors.forename: John
authors.initials: J
authors.lastname: Yarbrough
authors.forename: Andrew
authors.initials: A
authors.lastname: Norman
authors.forename: Kim
authors.initials: K
authors.lastname: Jones
authors.forename: Glenn
authors.initials: G
authors.lastname: Teeter
authors.forename: Fred Lewis
authors.initials: FL
authors.lastname: Terry
authors.forename: Dean
authors.initials: D
authors.lastname: Levi