Li_2SnO_3 branched nano- and microstructures with intense and broadband white-light emission

Abstract

Exploiting the synergy between microstructure, morphology and dimensions by suitable nanomaterial engineering, can effectively upgrade the physical properties and material performances. Li_2SnO_3 elongated nano-and microstructures in form of belts, wires, rods and branched structures have been fabricated by a vapor-solid method at temperatures ranging from 700 to 900 degrees C using metallic Sn and Li_2CO_3 as precursors. The achievement of these new morphologies can face challenging applications for Li_2SnO_3, not only in the field of energy storage, but also as building blocks in optoelectronic devices. The micro-and nanostructures grown at 700 and 800 degrees C correspond to monoclinic Li2SnO3, while at 900 degrees C complex Li_2SnO_3/SnO_2 core-shell microstructures are grown, as confirmed by X-ray diffraction and Raman spectroscopy. Transmission electron microscopy reveals structural disorder related to stacking faults in some of the branched structures, which is associated with the presence of the low-temperature phase of Li_2SnO_3. The luminescent response of these structures is dominated by intense emissions at 2, 2.5 and 3 eV, almost completely covering the whole range of the visible light spectrum. As a result, white-light emission is obtained without the need of phosphors or complex quantum well heterostructures. Enhanced functionality in applications such as in light-emitting devices could be exploited based on the high luminescence intensity observed in some of the analysed Li_2SnO_3 structures.