NEW DATA FROM YEREVAN STATE UNIVERSITY ILLUMINATE RESEARCH IN SENSOR RESEARCH

Journal of Technology & Science
March 15, 2009

According to recent research published in the IEEE Sensors Journal,
"Hydrogen sensor working at room and 40 degrees C temperatures made
of porous silicon covered by the TiO (2-x) or ZnO < Al > thin Him
was realized. Porous silicon layer was formed by electrochemical
anodization on a p- and n-type Si surface."

"Thereafter, n-type TiO2-x, and ZnO < Al > thin films were deposited
onto the porous silicon surface by electron-beam evaporation and
magnetron sputtering, respectively. Platinum catalytic layer and An
electric contacts were for further measurements deposited onto obtained
structures by ion-beam sputtering. The sensitivity of manufactured
structures to 1000-5000 ppm of hydrogen, propane-butane mixture,
and humidity wits studied. Sensitivity or obtained structures
was determined as ratio of the resistivity of structures in the
presence of investigated gas to that in air. Results of sensitivity
measurements showed that it is possible to realize a hydrogen
nanosensor, resistivity of which can be decreased up to 2.5 times at
room temperature and four times at 40 degrees C for the Pt/TiO2-x/PS
structure, as well as two times for the Pt/ZnO < Al >/PS structure
at 40 degrees C at 5000 ppm hydrogen concentration, respectively,"
wrote V. Aroutiounian and colleagues, Yerevan State University.

The researchers concluded: "Both structures have the recovery and
response time of approximately 20 s and rather high durability and
selectivity to hydrogen gas."

Aroutiounian and colleagues published their study in IEEE Sensors
Journal (Hydrogen Sensor Made of Porous Silicon and Covered by TiO2-x
or ZnO <Al> Thin Film. IEEE Sensors Journal, 2009;9(1-2):9-12).

For additional information, contact V. Aroutiounian, Yerevan State
University, Dept. of Physics Semicond & Microelect, Yerevan 0025,
Armenia.

The publisher’s contact information for the IEEE Sensors Journal is:
IEEE-Institute Electrical Electronics Engineers Inc., 445 Hoes Lane,
Piscataway, NJ 08855, USA.