PROPERTIES OF POLYCRYSTALLINE GAS SENSORS BASED ON DC AND AC ELECTRICAL MEASUREMENTS

被引：14

作者：

GUTIERREZ, FJ ^{[1
]}

ARES, L ^{[1
]}

ROBLA, JI ^{[1
]}

HORRILLO, MC ^{[1
]}

SAYAGO, I ^{[1
]}

AGAPITO, JA ^{[1
]}

机构：

[1] UNIV COMPLUTENSE MADRID,FAC FIS,DEPT ELECTR,E-28040 MADRID,SPAIN

来源：

SENSORS AND ACTUATORS B-CHEMICAL | 1992年 / 8卷 / 03期

关键词：

D O I：

10.1016/0925-4005(92)85023-P

中图分类号：

O65 [分析化学];

学科分类号：

070302 ; 081704 ;

摘要：

Electrical properties of polycrystalline gas sensors are analyzed by d.c. and a.c. measurements. d.c. electrical conductivity values compared with those obtained by admittance spectroscopy methods help to obtain a detailed 'on line' analysis of conductivity-modulated gas sensors. The electrical behaviour of grain boundaries is obtained and a new design of sensors can be achieved by enhancing the activity of surface states in the detecting operation. A Schottky barrier model is used to explain the grain boundary action under the presence of surrounding gases. The height of this barrier is a function of gas concentration due to the trapping of excess charge generated by gas adsorption at the interface. A comparison between this dependence, and a plot of the real and imaginary components of the admittance versus frequency at different gas concentrations, provides information on the different parameters that play a role in the conduction mechanisms. These methods have been applied to the design of a CO sensor based on tin oxide films for domestic purposes, the characteristics of which are presented.

引用

页码：231 / 235

页数：5

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