Synthesis and Characterization of TiO_2 Micro- and Nano-Structures with Variable Morphology and Aluminum Content

摘要

Achieving a high surface to volume ratio is of advantage in manyapplications of semiconducting oxides, which can be obtained by reducingthe size of the material toward the nanoscale. Beside size reduction,morphology variability and doping content could also induce differences inthe luminescence of structures in the micro- and nano-scale widening theirapplicability. Elongated rutile TiO_2 nano- and micro-structures are fabricatedby an evaporation-deposition method using TiN as precursor at temperaturesranging from 800 to 900℃. Aluminum doped TiO_2 micro- and nanostructuresare also grown at 940℃. The presence of Al hinders the growthof structures and retards the anatase to rutile transition. The as-grown lowdimensional structures are characterized by X-ray diffraction (XRD), scanningelectron microscopy (SEM), Raman spectroscopy, and cathodoluminescence(CL). The luminescence of the samples depends on the size,morphology, and aluminum content and is mainly dominated by anemission at 1.52 eV and weaker emissions at 2.45 and 2.9 eV, the origin ofwhich is discussed in this work.