Solution-synthesis of Sb2Se3 nanorods using KSeCN as a molecular selenium source

Abstract

Antimony selenide (Sb₂Se₃) is a low-toxic, element-abundant, narrow bandgap (E_g = ∼1.1–1.3 eV) semiconductor that shows potential for UV-Visible-Near-infrared optoelectronic applications. This paper reports the use of potassium selenocyanate (KSeCN) as a novel molecular selenium source to synthesize Sb₂Se₃ uniform nanorods. The resulting nanorods have been carefully characterized and are found to exhibit decent photoconductivity as well as broad-spectrum optical absorption with an E_g value of ∼1.35 eV. A molecular reaction mechanism is rationally proposed and evidenced for forming Sb₂Se₃, which is related to the thermal decomposition of selenocyanate (SeCN⁻) anions through the cleaving of Se–CN bonds to elemental Se(0), followed by its reduction to Se²⁻ anions. Our work using KSeCN offers an alternative method for the synthesis of metal selenides with desirable nanostructures and properties.