TeO_2纳米线的制备及其室温NO_2气敏特性

Preparation and Room-Temperature NO_2 Sensing Properties of TeO_2 Nanowires

以金属Te颗粒为原料,采用热蒸发法于镀金硅基板表面制备出TeO2纳米线,并以其为气敏材料制备成气敏元件.采用XRD,SEM和TEM表征TeO2纳米线的相组成和微观结构,结果表明,TeO2纳米线具有单一的四方相晶体结构,长度约为几十微米,直径约为80-600 nm.在TeO2纳米线的顶端未发现Au颗粒,表明TeO2纳米线按照气-固机制进行生长.气敏特性的研究结果表明,TeO2纳米线呈现p型半导体特性,在室温条件下对NO2气体具有良好的响应,气体灵敏度与NO2气体体积分数呈线性增加关系.最后对气敏机制进行了初步探讨.

TeO2 nanowires were synthesized on Au-coated Si substrate by thermal evaporation using Te metal as the source material.The gas sensor was prepared by using TeO2 nanowires as the sensing material.Microstructural characterization by means of XRD,SEM and TEM showed that TeO2 nanowires were single phase of tetragonal structure.The nanowires were approximately several tens of micrometers in length and 80 - 600 nm in diameter.No Au particles existed at the top of TeO2 nanowires,revealing that the growth of TeO2 nanowires occurred in vapor-solid mechanism.The gas sensing measurements indicated that TeO2 nanowires showed a p-type electrical conduction and reversible response to NO2 gas at room temperature.The sensitivity showed a linear increase with the increasing of NO2 gas volume fraction.The gas sensing mechanism of TeO2 nanowire sensor was investigated preliminarily.