Mesoporous single-crystal ZnO nanobelts: supported preparation and patterning

Abstract

We demonstrate that highly porous ZnO nanobelts can be prepared by thermally decomposing ZnS(en)(0.5) hybrid nanobelts (NBs) synthesized through a solvothermal route using Zn layers deposited on alumina substrates as both the Zn substrate and source. Hybrid decomposition by thermal annealing at 400 °C gives porous ZnS NBs that are transformed by further annealing at 600 °C into wurtzite single crystal ZnO nanobelts with an axial direction of [0001]. The evolution of the morphological and structural transformation ZnS(en)(0.5)→ ZnS → ZnO is investigated at the nanoscale by transmission and scanning electron microscopy analyses. Control of the ZnO NB distributions by patterning the Zn metallization on alumina is achieved as a consequence of the parent hybrid NB patterned growth. The presence of NBs on alumina in a ∼100 μm wide region between Zn stripes allows us to fabricate two contact devices where contact pads are electrically connected through a porous ZnO NB entanglement. Such devices are suitable for employment in photodetectors as well as in gas and humidity sensors.

Zn vacancy induced green luminescence on non-polar surfaces in ZnO nanostructures

“…Accordingly, the assessment of ZnO crystalline quality simply on the basis of the ratio between the NBE and GL may be misleading: indeed, this ratio is not inherently related to surface defects, since the intensity of the green band remarkably depends on the specific surface-to-volume ratio and morphology of the samples. This effect is in agreement with recent cathodoluminescence results on single crystal mesoporous ZnO nano-belts48.…”

S-induced modifications of the optoelectronic properties of ZnO mesoporous nanobelts

“…The mixture was stirred vigorously on a magnetic stir plate for 5 min on an alumina substrate where Zn metal patterns were previously defined by standard photolithography and lift off procedures so that the Zn area was kept to 1.5 cm 2 25. The metallized alumina substrate was then inserted into the liner, the autoclave was sealed, maintained at 200 °C in an oven for 24 h to grow ZnS( en ) 0.5 hybrid nanobelts, and finally cooled naturally to room temperature.…”

A general ligand-assisted self-assembly approach to crystalline mesoporous metal oxides

“…Mesoporous transition metal oxides possessing a large surface area and high degree of crystallization have attracted extensive attention because of their remarkable properties and promising applications in gas sensing, energy storage, catalysis, and photodetection [1][2][3][4][5][6][7][8] . Various strategies have been used to synthesize mesoporous transition metal oxides.…”