From Superconducting to Semiconducting YBCO Thin Film Bolometers: Sensitivity and Crosstalk Investigations for Future THz Imagers

YBa₂Cu₃O_6+x compounds are well known to exhibit superconducting properties for x > 0.5 and semiconducting properties for lower oxygen content. Superconducting YBCO was obtained commercially; the semiconducting material was deposited by sputtering close to room temperature (100degC, typically). In order to migrate from superconducting to uncooled semiconducting far-infrared bolometer technologies, we have compared the performance of 2 times 2 pixel arrays. Pixels were in the shape of meanders, embedded in an area of about 1 mm². Pixel detectivity and thermal crosstalk were studied in the 1 Hz to 100 kHz modulation frequency range by using a 850 nm solid state laser. Specific THz antenna concepts were also considered.