SnO_2基CO传感器敏感膜的电阻变化机理  

Resistance Change Mechanism of the Sensitive Film for SnO_2-Based CO Sensors

作　　者：何磊[1] 殷晨波[1] 张子立[1] 杨柳[1] 

机构地区：[1]南京工业大学机械与动力工程学院,南京211816

出　　处：《微纳电子技术》2016年第9期588-593,共6页Micronanoelectronic Technology

基　　金：国家自然科学基金面上资助项目(51575255)

摘　　要：应用基于密度泛函理论(DFT)的第一性原理,并借助Materials Studio软件中Castep模块建立了CO与SnO_2薄膜(110)面的吸附模型,最终确定了Pd掺杂的与纯净的SnO_2(110)面的最佳吸附位置分别为O_(2C)和Sn_(5C),吸附能分别为-1.842 5 eV和-0.533 3 eV。在此基础上,通过分析吸附体系电子态密度(DOS)及差分电荷密度的变化,阐明了SnO_2基CO气体传感器敏感膜的微观电阻变化机理及利用Pd掺杂能够改善气敏性能的原因。最后实验表明,Pd掺杂后SnO_2薄膜最佳工作温度由275℃降至200℃,灵敏度提高到30.1,验证了理论分析的结果。Using the first principle based on the density functional theory（DFT）and with the aid of the Castep module for Materials Studio software,the adsorption model of the（110）faces of the CO and SnO2 thin films was established,and the optimal adsorption positions of the pure and Pd-doped SnO2（110）faces were determined eventually to be O2Cand Sn（5C）,respectively.And the values of the adsorption energy for the positions of O2C and Sn（5C） were-1.842 5 eV and-0.533 3 eV,respectively.On this basis,the microscopic resistance change mechanism of the sensitive film for the SnO2-based CO sensor and the reason of the gas sensing property improved by doping Pd were illuminated through the analysis of the changes of the density of states（DOS）and differential charge density.Finally,the experiment indicates that the optimal working temperature of the SnO2 thin film decreases from275℃to 200℃after Pd-doping,the sensitivity increases to 30.1,thus the result of the theoretical analysis is verified.

关 键 词：第一性原理 SNO2 Pd掺杂 吸附能 敏感机理 气敏性能 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]