Effective heat conservation in a sandwich-structured microbolometer using mesoporous TiO2 layers

The heat loss of the a-Si:H resistor layer in a microbolometer might be reduced by using ordered mesoporous TiO2 thin films as thermal insulation layers. Infrared absorption of mesoporous TiO2 thin films in the 833–1250 cm−1 wave number region was measured using a Fourier transform infrared spectrometer. Also, the infrared absorption rates of upper and lower mesoporous TiO2 films inserted into the microbolometer were calculated to be above 84% in the 8–12 μm wavelength region. The CFD-ACE thermal simulation program was used to evaluate the thermal isolation effectiveness of mesoporous TiO2 films on the a-Si:H layer; the inclusion of this film on the a-Si:H layer improved heat conservation. A mesoporous TiO2 thin film effectively reduced the thermal loss from a-Si:H resistor surface and drastically increased the temperature of the resistor film.