Carbon-Based Substrates for Phonon Sensing: Results from First TES Detectors

We present the latest results on the calibration and characterization of our silicon carbide (SiC) based transition-edge sensor (TES) detectors, designed for rare-event searches. Developing detectors sensitive to eV scale energy deposition has been a subject of growing interest, with applications to both sub-GeV dark matter searches and coherent neutrino scattering . Carbon-based crystals, such as silicon carbide (SiC) and diamond are particularly well-suited for these searches due to carbon’s low atomic mass and its ability to form crystals with high-energy, long-lived phonon modes. Additionally, the high bandgap of these materials allows a high voltage bias with low leakage, which aids in the detection of charge events. We focus on calibration results, including energy resolution, phonon collection efficiency, and noise performance. The detector’s response to energy deposits from various wavelength light sources was measured, and the results compared to reference detectors on Si substrates. Additionally we present preliminary progress made fabricating these detectors on polycrystalline diamond.