非晶态SiO_2掺杂Fe^（2＋）薄膜气敏特性的研究

Study on the Gas-sensitive Speciality of the Noncrystaline SiO_2 Doped with Fe￣(2+)

研制成功一种以ＳｉＯ２作为主体，掺杂Ｆｅ２＋离子薄膜制备的气敏元件，对ＣＯ气体有良好的气敏特性。它的线性范围为１．２×１０－４～８．９２×１０－３ｍｏｌ·ｄｍ－３，检测下限为５×１０－５ｍｏｌ·ｄｍ－３３，响应速度≤５ｓ．本工作以非晶态半导体的Ｍｏｔｔ－Ｄａｖｉｓ能带模型结合表面吸附理论，初步探讨了该材料的气敏机理，确立了元件阻值Ｒ与吸附浓度Ｃ的关系方程，以此解释元件的气敏特性．该方程对非晶态ＳｉＯ２掺杂薄膜是普遍适用的。

SiO2 is used as the main body of the thin film and doped with Fe2+. It has high responsibility to the change of CO. The linearity of response is within the range of 1.2×10-4 -- 8.92×10-3 mol·dm-3. The detection limit is 5 ×10-5mol·dm-3. And the response time is no more than 5 s. In this work, the Mott-Davis Energy Band Model and the theory of surface adsorbtion is used to explain the work machanism of this material.And a equation of the resistance R and the adsorb density of CO is got. This equation is universally suitable for non-crystalline SiO2 doped thin film.