Highly stable ethylene glycol-capped blue-emitting antimony selenide quantum dots via hydrothermal approach

Abstract

A low-temperature hydrothermal method is adopted for the preparation of highly fluorescent antimony selenide quantum dots. Solution synthesis of such quantum dots with strong blue fluorescence is reporting for the first time and stands as the novelty of this work. Role of HCl and its significance in the quantum dot formation have been studied in detail. The presence of HCl is inevitable as it promotes the Sb2Se3 quantum dots formation and is a major inference obtained. Solution synthesis of Sb2Se3 involves two phases: nanoparticle formation and their partial dissolution—recrystallization to form quantum dots. Synthesized Sb2Se3 nanoparticles in 1 h have uniform morphology tending to one-dimensional growth confirmed using SEM and further increase in reaction time resulted in quantum dots with strong blue fluorescence and supramolecular structure in addition to nanoparticles whose formation was justified in support of UV, PL, XPS and Raman spectrum. The quantum dot solution remains stable for more than 20 months without any change in its optical response. Their temperature dependence was also studied to have an insight into size optimization and band-gap tuning. Optical response of this material was utilized for light absorption in solar cell.