| AVS 57th International Symposium & Exhibition | |
| MEMS and NEMS | Thursday Sessions |
| Session MN-ThA |
| Session: | Integration, Packaging and Reliability of MEMS and NEMS |
| Presenter: | A. Kumar, University of Central Florida |
| Authors: | A. Kumar, University of Central Florida P. Zhang, University of Central Florida H.J. Cho, University of Central Florida S. Seal, University of Central Florida |
| Correspondent: | Click to Email |
The growing need to explore hydrogen as a near future fuel demands a robust hydrogen sensor which offers high sensitivity, selectivity and response time in order to avoid the danger associated with storage, transportation and use of this highly combustible gas. The sensor platform with Au interdigitated electrodes (IDE) having 8 fingers in each electrode and a gap of 100 nm was fabricated using E-beam lithography on a silica substrate. The Au IDE was dip coated with sol-gel preparation of nanocrystalline 6.5 mol % Indium oxide (In2O3)- doped tin oxide (SnO2) to yield an excellent thin film room temperature hydrogen sensor. The variation in the I/V response of the sensor with atmosphere suggested that the Schottky barrier height could be modulated to sense hydrogen and utilizing this a large sensitivity (~2000) and fast response time (~27 seconds) was observed at a low applied voltage of 0.4 V in 0.09 vol% hydrogen gas atmosphere. The sensing characteristics were severely affected in presence of moisture (>40%). Various polymeric coatings on the sensor were compared in an effort to make the hydrogen sensor robust even in high moisture environment. It was observed that the fluoropolymer coatings improved the sensor behavior in varying moisture environment without deteriorating other characteristics such as sensitivity, response time and recovery of a sensor.