Photoluminescence of oxygen vacancies and hydroxyl group surface functionalized SnO_2 nanoparticles

Abstract

We report, for the first time, the luminescence property of the hydroxyl group surface functionalized quantum dots (QDs) and nanoparticles (NPs) of SnO_2 using low energy excitations of 2.54 eV (488 nm) and 2.42 eV (514.5 nm). This luminescence is in addition to generally observed luminescence from 'O' defects. The as-prepared SnO_2 quantum dots (QDs) are annealed at different temperatures in ambient conditions to create varied NPs in size. Subsequently, average size of the NPs is calculated from the acoustic vibrations observed at low frequencies in the Raman spectra and by the transmission electron microscopic measurements. Detailed photoluminescence studies with 3.815 eV (325 nm) excitation reveal the nature of in-plane and bridging 'O' vacancies as well as adsorption and desorption occurred at different annealing temperatures. X-ray photoelectron spectroscopy studies also support this observation. Defect level related to the surface -OH functional groups shows a broad luminescence peak around 1.96 eV in SnO_2 NPs which is elaborated with the help of temperature dependent studies.

10 pages, 11 figures, journal

References in corpus (3)

• Ferromagnetism as a universal feature of nanoparticles of the otherwise nonmagnetic oxides
• Influence of in-plane and bridging oxygen vacancies of SnO_2 nanostructures on CH_4 sensing at low operating temperatures
• Surface functionalization enhanced magnetism in SnO_2 nanoparticles and its correlation to photoluminescence properties

Cited by in corpus (2)

• Electrochemical supercapacitor performance of SnO2 quantum dots
• Invoking forbidden modes in SnO_2 nanoparticles using tip enhanced Raman spectroscopy