UV-visible absorption and photoluminescence characteristics of SnO2 nano-tube/wire arrays fabricated by LPD method

Abstract

In this study, SnO2 nano-tube/wire arrays with a diameter in the range of 90-120 nm and several micrometers in length were synthesized by the liquid phase deposition (LPD) method. The study of structural properties was performed by XRD, Raman and TEM, while the optical properties were measured using UV-visible absorption and photoluminescence spectroscopy. The Raman spectra of the nano-tubes/wires revealed the presence of 5 vibration peaks assigned to the tetragonal rutile SnO2 structure in agreement with the XRD results. The estimated optical direct band gap from UV-visible absorption spectra was found to be 3.73- 3.88 eV. The observed blue shift of the optical band gap can be explained by the higher formation of mesoporous particles on the exposed surface to the photons. The photoluminescence (PL) spectra of the nano-tubes/wires exhibited a rather broad and intense emission band centered at around 560-569 nm.