Preparation of macroporous Eu-doped oxide thick films and their application to gas sensor materials

Abstract

Macroporous (mp-)SnO 2 thick films doped with 5 mol% Eu and 0∼10 mol% Mg (Lmp-SnO 2(mMg):Eu, L: the size of PMMA microsphere used: 400 or 800 (nm), m: Mg content) were fabricated by a modified sol-gel method that employs PMMA microspheres as a template and constituent metal chlorides as an oxide source. The photoluminescence (PL) intensity due to Eu 3+ ions increased with increasing the Mg content in the thick films. These films were subjected to the PL response measurement to acetone, and their PL intensities decreased clearly upon exposure to acetone balanced with air. Among all the films tested, Lmp-SnO 2(1Mg):Eu showed the highest ratio (I 0/I) of PL intensity in air (I 0) to that (I) in acetone, irrespective of the size of macropores, while the signal/noise (S/N) ratio was low. On the other hand, ΔI (= I 0 -I) of Lmp-SnO 2(mMg):Eu was the highest at m = 10 with a high S/N ratio. © 2008 The Institute of Electrical Engineers of Japan.