Challenges of producing TiO2 films by microwave heating

Microwave processing is an attractive alternative to conventional furnace treatment for sintering of TiO2 nanostructured thin films. When heated with 2.45-GHz microwaves, it was found that conducting glass cracked when a temperature above ∼200 °C was reached. Coating a ∼20-μm-thick film of nanostructured TiO2 on the transparent conducting oxide (TCO) glass (using a commercially available powder) raised the temperature at which cracking occurred to ∼400 °C. When a sol-gel method was used to produce TiO2, difficulties were encountered in the production of ∼10-μm-thick films, including cracking of films during drying.