图案化氧化钨纳米线阵列的低温制备工艺及其场发射特性研究

A Low-Temperature Method to Selected-Area Synthesis of Tungsten Oxide Nanowire Arrays and Investigation on Their Field Emission Properties

氧化钨纳米线由于具有长径比较大、导电性好、阈值电场较低、可承受的电流较高等优点,因此在场致电子发射器件中受到人们的广泛关注。但是在氧化钨纳米结构研究发展的过程中,出现了一些技术难题,比如制备温度高(>800℃),制备的氧化钨通常混合多种化学相而导致物性不均匀等,所以束缚了氧化钨纳米线在场发射领域的快速发展。本文采用磁控溅射技术结合化学气相沉积技术在500℃下分别实现了高纯相的WO2和WO3纳米线阵列的定域生长。场发射特性研究结果表明:所制备的WO3纳米线阵列的开启电场低至0.65MV/m,阈值电场约为2.9MV/m,最大电流密度达到18.3A/cm2;WO2纳米线阵列的开启电场低至0.8MV/m,阈值电场为2.46MV/m,最大电流密度达到12.1mA/cm2。这表明在低温下制备的氧化钨纳米线阵列在场致电子发射领域具有非常广阔的应用前景。

WO3 -x （0≤x〈 3） nanostructures are very attractive for field emitters because their low threshold field, high aspect ratio and high current density capacity. But in their development, there are many technique problems existing in their applications, such as high-temperature needed for growing, mixed phases conexisting which cause nonuniform. By adjusting the type of catalysts, the controlled growth of micro-patterned WO2 and WO3 nanowire arrays have been firstly realized at low temperature （450 to 600℃）. It is found that the turn-on field and threshold field of micro-patterned WOz nanowire ar- rays is respectively 0.8 MV/m and 2.46 MV/m. And the turn-on field and threshold field of micro-pat- terned WO3 nanowire arrays are found to be 0.65 MV/m and 2.9 MV/m, respectively. Their very excel- lent FE performance suggests that this novel growth method is a useful technique for low-temperature preparation of micro-patterned nanoemitter cathode arrays.