Growth and luminescence properties of micro- and nanotubes in sintered tin oxide

Abstract

Sintering SnO 2 under argon flow at temperatures in the range of 1350-1500°C causes the formation of wires, rods, and tubes on the sample surface. At high temperatures of the mentioned range, microwires with lengths of hundreds of microns are formed. At lower temperatures the formation of micro-and nanorods as well as micro-and nanotubes takes place. The influence of ball milling of the starting powder on the formation of tubes is investigated. The local cathodoluminescence measurements show a different defect structure in the tubes than in the sample background.

Thermal growth and structural and optical characterization of indium tin oxide nanopyramids, nanoislands, and tubes

“…As shown in Figs. 6͑b͒ and 6͑d͒, both small and pyramidal islands present a similar behavior. The tubes show an enhanced CL emission from their inner part as has been previously observed in undoped SnO 2 tubes, 8 which is related to the characteristic distribution of defects. Figure 7 shows a region of the XPS spectrum of the starting mixture used to prepare sample 2:1, where the O ͑1s͒, In ͑3d͒, and Sn ͑3d͒ core levels peaks can be observed.…”

“…Rectangular SnO 2 tubes have been previously grown by the same thermal method described here, when pure SnO 2 powder was used as precursor. 8 As discussed in Ref. 8, the most probable growth direction of the tubes is ͓101͔ and the narrow and wide lateral surfaces of the rectangular tube would be the ͑010͒ and ͑10− 1͒ planes, respectively.…”

“…8 As discussed in Ref. 8, the most probable growth direction of the tubes is ͓101͔ and the narrow and wide lateral surfaces of the rectangular tube would be the ͑010͒ and ͑10− 1͒ planes, respectively. The present results show that the growth of the tubes, with morphology related to the SnO 2 tetragonal structure, takes place only when the starting mixture contains a high fraction of SnO 2 , at least the 1:2 ratio.…”

“…8,14 Since the tubes grown in this work contain only about 1 at. % of In, we suggest that the CL emission from the tubes ͓Fig.…”

“…This method has been previously reported to lead to the growth of elongated structures of different semiconductor oxides on the surface of the sample, so that neither a catalyst nor a foreign substrate is used. [8][9][10][11][12][13] In Ref. 8, the growth of SnO 2 microand nanotubes with rectangular cross section was reported, while in the case of In 2 O 3 , 11 wires, necklace-and arrowshape structures were grown from InN.…”