ZnO纳米线/纳米棒混合阵列的制备及其光致发光性能研究

Preparation and Photoluminescence Properties of ZnO Nanowire/Nanorod Mix Arrays

使用无催化剂热蒸发法,在ZnO/Si薄膜衬底上制备了ZnO纳米线/纳米棒混合阵列。其中,纳米线的直径为10~20 nm,纳米棒的直径为60~160 nm,二者混合在一起垂直生长于衬底表面。从衬底的上游到下游位置,混合阵列中纳米线的含量逐渐下降,纳米棒逐渐增多。室温光致发光测试发现尺寸较小的纳米线阵列的紫外光发光强度比大尺寸纳米棒阵列高约5倍。持续激发光照射下,纳米线阵列的发光强度逐渐上升,停止光照后又逐渐下降到初始值,这可以用纳米线表面O2分子的解吸附和吸附过程来理解。

Well-aligned ZnO nanowire/nanorod mixed arrays were synthesized on ZnO/Si thin film substrates by a catalyst-free thermal evaporation method.The nanowires and nanorods with diameters of 10-20 nm and 60-160 nm,respectively,were mixed together in the arrays.The ratio between the numbers of nanowires and nanorods was decreasing in the downstream direction on the substrate.Room-temperature photoluminescence measurements showed that the ultraviolet emission intensity of the nanowire arrays was about 5 times higher than that of the nanorod arrays.Continuous illumination with incident laser serves to enhance the ultraviolet emission of the nanowire arrays,and the emission intensity decreased to the original value without the illumination,which could be interpreted by the desorption and adsorption of the oxygen species on the nanowire surface.