Influence of surfactant on the structural, morphological and optical properties of SrWO4: Insights through electron density distribution analysis

Scheelite-type surfactant-assisted SrWO4 was prepared via a simple co-precipitation method. The effect of various surfactants such as hexamethylenetetramine, polyvinylpyrrolidone, and sodium dodecyl sulphate, on the structural, morphological and photoluminescence (PL) properties of SrWO4 was investigated. Powder X-ray diffraction and the Rietveld profile refinement technique confirmed the tetragonal structure of all the as-synthesized SrWO4 materials. Among the three surfactants, particles with spherical morphology were observed for SDS-assisted SrWO4. Surfactant-assisted SrWO4 exhibited bluish-green emission around 500 nm, ascribed to the presence of WO42-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\left( {{\text{WO}}_{4}^{2 - } } \right)$$\end{document} luminescence centre at 284 nm excitation, and the PL emission intensity significantly increased in the presence of surfactant. Electron density distribution analysis of a single unit cell for all the prepared materials was investigated, and correlated with the PL results.