Effect of alumina addition on methane sensitivity of tin dioxide thick films

Alumina is often used as a binder and/or stabilizer in tin dioxide gas sensors. In the present work, we have studied the role of alumina on the electrical properties and gas (methane) sensitivity of tin dioxide thick films. It has been observed that alumina, even without entering into the lattice of tin dioxide, can improve the sensitivity of tin dioxide sensors. Such behaviour can be interpreted by considering electronic interaction between the semiconducting tin dioxide grains and the Lewis acid sites of alumina grains in close contact.