Porous silicon near room temperature nanosensor covered by TiO2 or ZnO thin films

Abstract

Hydrogen nanosensor working near room temperature made of porous silicon covered by the TiO2-x or ZnO thin film was realized. Porous silicon layer was formed by electrochemical anodization on a p- and n-type silicon surface. Thereafter, n-type TiO2-x and ZnO thin films were deposited onto the porous silicon surface by electron-beam evaporation and magnetron sputtering, respectively. Platinum catalytic layer and gold 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 was studied. Results of measurements showed that it is possible to realize a hydrogen nanosensor which has relatively high sensitivity and selectivity to hydrogen, durability, and short recovery and response times. Such a sensor can also be a part of silicon integral circuit and work near room temperatures.