SnO2 hierarchical nanostructure and its strong narrow-band photoluminescence

A hydrothermal method was developed for the fabrication of the hierarchical SnO2nanostructure with interstitial Sn2+ (Sni). Eleven narrow emissions occurred in the photoluminescence spectra after annealing at above 900 °C, which have never been reported for the un-doped SnO2. The narrow emissions are well explained as the result of electron transitions among energy levels in Sni. Detailed structural investigation and analysis revealed the important role of the intermediate SnO in the formation of the hierarchical nanostructure and the interstitial Sn2+.