Determination of Thermal Parameters of Vanadium Oxide Uncooled Microbolometer Infrared Detector

Vanadium oxide thin films are the potential candidates for uncooled microbolometers due to their high temperature coefficient of resistance (TCR) at room temperature. A 2D array of 10-element test microbolometer without air-gap thermal isolation structure was fabricated with pulsed laser deposited vanadium oxide as IR sensing layer for the first time. Infrared responsivity of the uncooled microbolometer was evaluated in the spectral region 8-15 μm. The device exhibits responsivity of about 12 V/W at 30 Hz chopper frequency for 20 μA bias current. Thermal time constant (τ), Thermal conductance (G) and thermal capacitance (C) are the thermal parameters characterize the performance of the uncooled microbolometer infrared detectors are determined as 15 ms, ～10^-3 W/K and ～3.5 × 10^-5 J/K respectively. The influence of the thermal parameters on the performance of the microbolometer is discussed.