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

oleh: Max Birkett, Wojciech M. Linhart, Jessica Stoner, Laurie J. Phillips, Ken Durose, Jonathan Alaria, Jonathan D. Major, Robert Kudrawiec, Tim D. Veal

Format: Article
Diterbitkan: AIP Publishing LLC 2018-08-01

Deskripsi

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.