بلورة تلتقط غير المرئي سريع

الملخص الأصلي

كما كتبه المؤلفون، بالإنجليزية arXiv:2601.08934

Rare-event searches including dark matter, coherent elastic neutrino--nucleus scattering (CE$$ u$$NS), and neutrinoless double-beta decay (0$$ u\beta\beta$$) require high-purity germanium (HPGe) detectors with ultralow noise, stable backgrounds, and electrode geometries that can scale to larger single-crystal masses. Ring-contact (ring-and-groove) designs address scalability by shaping the electric field to preserve low-capacitance readout, but their nonplanar topology motivates a lithium-contact process that is compatible with conformal deposition and robust high-voltage operation. As a process demonstration toward future ring-contact prototypes, we fabricate and characterize a hybrid-contact planar HPGe device, KL01. Here, ``hybrid'' denotes an $$n^{+}$$ contact formed by an in-house lithium-suspension paint followed by controlled thermal diffusion, combined with an AJA-developed a-Ge/Al $$p^{+}$$ contact and a-Ge sidewall passivation. At 77~K the device exhibits pA-scale leakage current under kV bias, a depletion plateau near $$V_{\mathrm{dep}}\approx 1300$$~V, and energy resolutions of 1.57~keV FWHM at 59.5~keV and 2.57~keV FWHM at 662~keV. These results validate the compatibility of the paint-and-diffuse lithium process with thin-film a-Ge/Al contacts and establish a practical fabrication workflow to be extended to ring-and-groove electrodes for next-generation rare-event HPGe modules.