Physical properties of amorphous molybdenum silicide films for single-photon detectors. (4th August 2021)

• Record Type: Journal Article
• Authors: Zhang, Xiaofu; Charaev, Ilya; Liu, Huanlong; Zhou, Tony X; Zhu, Dong; Berggren, Karl K; Schilling, Andreas
• Is Part Of: Superconductor science & technology. Volume 34:Number 9(2021)
• Publication Date: 2021-08-04
• Subjects: thin films -- single-photon detectors -- SNSPDs -- superconducting detectors -- superconducting films -- magnetic field; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/1361-6668/ac1524
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: We systematically investigated the physical properties of amorphous Mo x Si1− x films deposited by magnetron co-sputtering. The critical temperature T c of Mo x Si1− x films increases gradually with the Mo stoichiometry x, and the highest T c = 7.9 K was found in Mo0.83 Si0.17, where homogeneous films with the maximum Mo content can be obtained. The thick films of Mo0.83 Si0.17 show surprising degradation in which the onset of zero-resistivity is suppressed below 2 K. The thin Mo0.83 Si0.17 films, however, reveal robust superconductivity even with thickness d ≍ 2 nm. We also characterized wide microwires based on the 2 nm thin Mo0.8 Si0.2 films with wire widths 40 and 60 μ m, which show single-photon sensitivity at 780 nm and 1550 nm wavelength.