The characteristic in infrared region of the TiO₂:Ti film

The TiO₂:Ti film was prepared as an alternative of the absorber layer for infrared thermal detectors. The as-deposited film was composed of TiO₂ and Ti with a ratio near 5:1. To improve its absorption in infrared region, the film was etched in the diluted H₂O₂ solution. The etching process made the film porous and reduced the concentration of the free electron in the etched film, which decrease the reflection of the films and subsequently increase their absorption. The maximum absorption of the acid-treated Ti-based film was about 90% for the infrared radiation near 1500 cm^-1. The resistivity of the etched films has been derived from four probe method with a two-layer model and from infrared spectrum by simulating it with Drude model. The values of resistivity from the two methods are in good agreement.