中文摘要：

采用化学共沉淀法制备了Oat％，5at％，7at％，9at％四种不同sn掺杂ZnO前驱体。经退火处理得到不同sn掺杂的ZnO粉末。通过x射线衍射仪和扫描电子显微镜对不同样品的晶体结构和表面形貌进行表征。利用浸渍法制作气敏元件，并测试其气敏特性。结果表明：sn掺杂ZnO具有六方纤锌矿结构，尺寸分布均匀，且六棱柱表面呈粗糙多孔状。在65℃工作温度及光照条件下，7at％Sn掺杂ZnO元件对乙醇气体表现出较好敏感特性，响应和恢复时间分别为1s和5s，灵敏度达到400。针对气敏特性的改善，结合表面吸附理论和光激活理论对气敏机理进行了进一步探讨。

英文摘要：

Pure ZnO and 5at%, 7at%, 9at% Sn-doped ZnO precursors were prepared by the chemical co-precipitation method. Different Sn-doped ZnO powers were obtained by annealing. The crystal structure and surface topography of different samples were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Gas sensors were prepared by dip coating method. The sensing properties were tested. The results show that the Sn-doped ZnO materials appear rough porous structures with the hexagonal wurtzite. The particle size distribution was uniform. The maximum sensitivity could be achieved by doping the amount of 7at%. It has much better sensing performance towards ethanol vapor under visible light irradiation. The response and recovery time were 1 s and 5 s, respectively. The sensitivity is 400. The mechanism for the improvement in the sensing properties could be explained with the surface adsorption theory.