Application of nano-crystalline porous tin oxide thin film for CO sensing

Nano-crystalline porous tin oxide thin film was successfully prepared by a sol-gel technique and evaluated for CO sensing. The surface morphology, ele ctrical conductance and CO sensitivity of the tin oxide thin films calcined at various temperatures (500-800 degrees C) were studied and compared. The particles were in the diameter range of 7-15 nm and the pore diameters wer e about 1.6-9 nn. The tin oxide film calcined at 700 degrees C deposited on to interdigitated electrodes showed high CO sensitivity with relatively fas t response (similar to 4 min) and recovery time (similar to 1 min), respect ively. The results indicate the advantages of using nano-crystalline porous materials for thin him sensor development. (C) 1998 Elsevier Science S.A. All rights reserved.