可鉴别室内有害气体的铟锡氧化物薄膜气敏特性研究

采用无机试剂SnCl2·2H2O及InCl3*4H2O为原料,用溶胶-凝胶提拉法制备了铟锡比不同的氧化铟锡薄膜构成的气敏传感器阵列,并对薄膜的电学性能及气敏性能进行了表征.结果表明,不同铟锡比组成的氧化铟锡薄膜不但载流子浓度不同,而且导电类型也不同,即阵列中每个传感器薄膜的载流子浓度和导电类型是不同的.当气体分子与阵列中的传感器表面接触时,由于载流子种类、载流子浓度、费米能级等的不同,导致电荷转移情况也不同,使得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.

Fabrication and Testing of Indium-Tin-Oxide Thin-Film Gas-Sensor-Array for Indoors Hazerdous Gases Detection

Thin??film gas??sensor??array of indium??tin??oxide were fabricated by sol??gel dip??coating process using SnCl2??2H2O and InCl3 ??4H2O as source materials for tin and indium. The In/ Sn ratio of individual sensor film was differentfrom each other, leading to the formation of a gas??sensor??array in which the carrier concentration, the carrier type, andthe Fermi level of each sensor film were different , determined by the Hall effect measurement. The conducting type ofthe sensor f ilm is n??type when In/ Sn low, or close to unity, while it is p??type when In/ Sn is in the intermediaterange. Gas detection measurements of the array show good selectivity for four common indoor hazardous gases ( formal??dehyde, benzene, dimethyl benzene, methyl benzene) . It is suggested that charge transfer between the absorbing gasesand the sensor films are different for each sensor because of different Fermi level of the sensor film caused by differentcarrier concentration and different conducting type, which increased the selectivity of the sensor array.