Substrate and Device Pattern Dependence of the Thermal Crosstalk in Y Ba$_2$Cu$_3$O$_{7-\delta}$ Transition Edge Bolometer Arrays

Abstract

Abstract-Using YBa 2 Cu 3 O 7(YBCO) thin films, pulsed laser deposited on 1-mm-thick LaAlO 3 or SrTiO 3 substrates, we made 4 1 pixel arrays of transition edge bolometers with separations between neighboring pixels ranging from 40 m to 170 m for testing purposes. We investigated the effects of the YBCO film thickness (200 and 400 nm), substrate material, and back-etching of the substrate, on the crosstalk between the pixels of the arrays. The investigation was based on the analysis of the voltage response of the dc current biased bolometers versus the modulation frequency of a near-infrared laser source. We observed that the bolometer arrays made of 400-nm-thick films had less interpixel thermal crosstalk than the 200-nm-thick films. The effect of substrate thickness on the response of the pixels was investigated by up to 500 m back-etching of the substrates. The bolometers made on back-etched LaAlO 3 substrates had anomalous crosstalk response behavior, which was effective at higher modulation frequencies. In addition, we present an analytical thermal model for explaining the observed effects of the thermal crosstalk on the response characteristics of the pixels of the arrays. We report the measured response and the anticipated thermal crosstalk of the characterized bolometers'. We describe the responses based on the thermal models and discrepancies from the model's predictions.

Effective Thermal Properties of a HTS Transition Edge Bolometer for High‐Flux Neutron Detection

“…This was shown for HTS bolometer devices with feature sizes of 40–170 µm that showed significant cross‐talk up to a cut‐off frequency of 1–15 kHz depending on geometry. [ 31 ]…”

“…This was shown for HTS bolometer devices with feature sizes of 40-170 μm that showed significant cross-talk up to a cut-off frequency of 1-15 kHz depending on geometry. [31] For future designs it would be recommendable to make geometric adjustments to the design, where the superconducting meander has a higher filling factor to lower the effect of g. With the current fabrication methods a filling factor of at least 70% is possible. Adjusting the interface thermal conductivities between pixel, substrate and cold finger by adjusting the stack geometry and fabrication process would make it possible to optimize the detector for specific applications.…”

Analytical modelling of the interpixel thermal crosstalk in superconducting edge-transition bolometer arrays

“…In the previous section, we chose an arbitrary sample's data and demonstrated the derivation and physical basis of the model. We have already reported the qualitative analysis of the effects of the physical parameters of the devices on the thermal crosstalk between the devices of an array [6,13], and hence we will not get into the details here. In this section, we present the results of applying the model to devices of various physical parameters and verify its validity and test its range of applicability.…”