Hydrogen Sensor Based on Pd∕GeO[sub 2] Using a Low Cost Electrochemical Deposition

Abstract

This work reports on a synthesis of sub micron germanium dioxide (GeO 2 ) on porous silicon (PS) by electrochemical deposition. n-type Si (100) wafer was used to fabricate (PS) using conventional method of electrochemical etching in HF based solution. A GeCl 4 was directly hydrolyzed by hydrogen peroxide to produce pure GeO 2 , and then electrochemically deposited on PS. Followed by palladium (Pd) contact on GeO 2 /PS was achieved by using RF sputtering technique. The grown GeO 2 crystals were characterized using SEM and EDX. I-V characteristics of Pd/ GeO 2 were recorded before and after hydrogen gas exposure as well as with different H 2 concentrations and different applied temperatures. The sensitivity of Pd/ GeO 2 also has been investigated it could be seen to increase significantly with increased hydrogen concentration while it decreased with increase temperature.