【作者】 孙兰侠；

【导师】 季振国；

【作者基本信息】 浙江大学 ， 材料物理与化学， 2005， 硕士

【摘要】 本论文综述了SnO₂薄膜的制备工艺,掺杂和未掺杂SnO₂薄膜的基本性质及在各个领域中的应用,并从提高气体传感器的选择性,降低气体传感器的工作温度着手开展了一些研究。利用Sol—gel法制备了钢锡比不同的铟锡氧化物薄膜,对薄膜的电学性能及气敏性能进行了表征,并由此构成了P-N组合型气敏传感器阵列。结果表明,由于不同铟锡比组成的氧化铟锡薄膜内载流子浓度不同,而且导电类型也可能不同,因此气敏传感器阵列中每个传感器对气体的响应也不同,使得气敏传感器阵列具有很好的选择性。通过对甲醛、苯、甲苯、二甲苯的测试,证明此阵列对四种室内污染气体具有较好的选择性。另外本文还研究了二氧化锡薄膜气敏传感器在常见室内污染气体气氛中的电阻-温度变化关系。结果发现不同气氛下电阻-温度曲线的特性各不相同,由此可以获得被测气体的相关信息,提高传感器的选择性。本文还用分子轨道计算软件（WinMOPAC2.0）对四种室内污染气体的分子轨道进行了计算,并根据分子轨道能级的相对位置从理论上定性解释了二氧化锡薄膜气敏传感器在不同气氛中的电阻-温度曲线。 此外,我们还发明了一种全新的制备纳米ZnO薄膜的方法,并用多种手段对它进行了表征。然后在不同的温度下测量了纳米氧化锌薄膜对几种有害气体的响应,结果发现这种以纳米氧化锌为气敏膜的气体传感器在室温就对四种常见室内污染气体有很好的灵敏度。更多还原

【Abstract】 The preparation, characteristic and application in different fields of undoped and indium doped SnO₂ thin films were described in this paper. The study was focused on the improvements of the selectivity and low temperature operation of the gas sensors. Indium doped tin oxide thin films with different In/Sn ratio, and a P-N combined gas-sensor-array based on the p and n type tin oxide was fabricated by sol-gel method. The electronic properties and gas sensitivities of the above mentioned sensors were characterizedThe results showed that the carrier concentration and conducting type of the oxide films varies as the In/Sn ratio changes. So the response of each individual sensor to specific gases in the gas-sensor-array was different, which lead to the excellent selectivity of this array. Gas detection measurement of the array showed good selectivity for 4 common hazardous indoors gases （formaldehyde, benzene, methylbenzene, and dimethyl benzene）. The resistance-temperature relation （R-T） of a gas sensor based on undoped SnO₂ film was also studied in this paper. It is found that in R-T curve, different gases have different slopes, which could be used to distinguish gases, thus increases the selectivity of the gas sensor. Molecule orbital energies of above mentioned four common hazardous gases calculated using WinMOPAC 2,0 indicated differences in the energy of the lowest unoccupied molecule orbital （LUMO） was responsible for the different slope in R-T curves.In addition, a thin films gas sensor based on nano-ZnO were prepared by a new method invented by our group. The response of nano-ZnO thin films to several common hazardous gases have been measured, the results showed that gas sensor based on such nano-ZnO particle films are of high sensitivity for above mentioned four common indoors hazardous gases even at room temperature.更多还原