The candidate photovoltaic absorber antimony selenide Sb 2 Se 3 has been prepared by
the commercially attractive close-space sublimation method. Structure, composition, and
morphology are studied by x-ray diffraction, scanning electron microscopy, and energy
dispersive spectroscopy. Large rhubarb-like grains favorable for photovoltaics naturally
develop. The temperature-dependence of the direct band gap is determined by
photoreflectance between 20 and 320 K and is well described by the Varshni and Bose …