Band gap temperature-dependence of close-space sublimation grown Sb2Se3 by photo-reflectance

• Published in: APL materials 2018-08, Vol.6 (8), p.084901-084901-8
• Main Authors: Birkett, Max, Linhart, Wojciech M., Stoner, Jessica, Phillips, Laurie J., Durose, Ken, Alaria, Jonathan, Major, Jonathan D., Kudrawiec, Robert, Veal, Tim D.
• Format: Article
• Language: English
• ISSN: 2166-532X; 2166-532X
• DOI: 10.1063/1.5027157

The candidate photovoltaic absorber antimony selenide Sb2Se3 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–Einstein relations, blue-shifting with decreasing temperature from 1.18 to 1.32 eV. The 300 K band gap matches that seen in high quality single-crystal material, while the 0 K gap is consistent with that found in first-principles calculations, further supporting the array of beneficial photovoltaic properties indicated for this material.