Enhanced bolometric properties of TiO2-x thin films by thermal annealing

Abstract

The effect of thermal annealing on the bolometric properties of TiO2-x films was investigated. The test-patterned TiO2-x samples were annealed at 300 degrees C temperature in order to enhance their structural and electrical properties for effective infrared image sensor device applications. The crystallinity was changed from amorphous to rutile/anatase in annealed TiO2-x films. Compared to the as-deposited samples, a decrement of the band gap and a decrease of the electrical resistivity were perceived in annealed samples. We found that the annealed samples show linear current-voltage (I-V) characteristic performance, which implies that ohmic contact was well formed at the interface between the TiO2-x and the Ti electrode. Moreover, the annealed TiO2-x sample had a significantly low 1/f noise parameter (1.21 x 10(-13)) with a high bolometric parameter (b) value compared to those of the as-deposited samples. As a result, the thermal annealing process can be used to prepare TiO2-x film for a high-performance bolometric device.