单晶TiO_2纳米线束阵列的水热合成及场发射性能研究

Hydrothermal Synthesis and Field Emission Performance of Single Crystalline TiO_2 Nanowires Bundle Arrays

采用水热合成技术,以钛酸丁酯、盐酸和去离子水作为前驱物,在透明导电玻璃（FTO）衬底上合成了垂直于衬底生长的二氧化钛（TiO2）纳米线束阵列。纳米线束呈四方柱状结构,宽度100-200 nm,长度约3μm。HRTEM表明每根纳米线束实际上是由20-40根直径约为4-6 nm的细小纳米线聚集在一起而形成的。系统研究了盐酸浓度对纳米线生长的影响,分析了盐酸在晶体生长中的作用。研究了TiO2纳米线束阵列的场致电子发射特性,其场发射开启电场为5.7 V/μm（对应电流密度10μA/cm2）,阈值电场为9.5 V/μm,同时表现出较好的场发射稳定性。低的合成温度和好的场发射性能表明TiO2纳米线束阵列在场发射冷阴极器件上具有良好的应用前景。

Vertically aligned single-crystalline TiO2 nanowire bundles array were synthesized on transparent conductive fluorine-doped tin oxide（FTO） substrates by hydrothermal method using tetrabutyl titanate and hydrochloric acid as precursors.The nanowire bundles have flat tetragonal crystallographic planes with the section of 100-200 nm and the length of 3 μm.HRTEM indicate that each nanowire bundle is composed of 20-40 tiny nanowires.The tiny nanowires have the diameter of 4-6 nm.Field emission results of the TiO2 nanowire bundles show a turn-on field of 5.7 V/μm at a current density of 10 μA/cm2.The threshold field is 9.5 V/μm.The emission current is relatively stable.The low synthesis temperature and good field emission performance show that the TiO2 nanowire bundles have good potential application in field emission cold cathode device.