ZnO-Nanorod-Based Ammonia Gas Sensors With Underlying Pt/Cr Interdigitated Electrodes

Author

Chen, Tai-You ; Chen, Huey-Ing ; Hsu, Chi-Shiang ; Huang, Chien-Chang ; Wu, Jian-Sheng ; Chou, Po-Cheng ; Liu, Wen-Chau

Author_Institution

Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan

Volume

33

Issue

10

fYear

2012

Firstpage

1486

Lastpage

1488

Abstract

ZnO-nanorod-based resistor-type ammonia gas sensors with underlying Pt/Cr interdigitated electrodes have been fabricated and investigated. The response is improved by reducing the electrode spacing d. Experimentally, a high response of 80.6 is found when d is reduced to 2 μm under exposure to a 1000-ppm NH₃ /air gas at 300 ^°C. A lower detection limit of 10-ppm NH₃/air at 300 ^°C is also obtained. This device possesses response and recovery times of <; 3 min even at low ammonia concentrations (10 ppm). The enhanced ammonia-sensing capability with reducing electrode spacing d could be attributed to the formation of more ZnO grain boundaries. A simple cross-linked structure model is presented to interpret the ammonia-gas-sensing performance, and a good correlation between theory and experiment is demonstrated.

Keywords

II-VI semiconductors; ammonia; chromium; electrodes; gas sensors; nanofabrication; nanorods; nanosensors; platinum; wide band gap semiconductors; zinc compounds; ZnO-NH₃-Pt-Cr; ammonia concentrations; cross-linked structure model; electrode spacing reduction; enhanced ammonia-sensing capability; interdigitated electrodes; nanorod-based resistor-type ammonia gas sensors; temperature 300 degC; Electrodes; Gas detectors; Resistance; Strontium; Time factors; Zinc oxide; $hbox{NH}_{3}$ ; Nanostructure; ZnO; sensor;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2012.2208729

Filename

6287546