Superconducting nanowire single photon detectors fabricated from an amorphous Mo0.75Ge0.25 thin-film
Varun B. Verma, Adriana E. Lita, Michael R. Vissers, Francesco Marsili, David P. Pappas, Richard P. Mirin, Sae Woo Nam
We present the characteristics of superconducting nanowire single photon detectors (SNSPDs) fabricated from amorphous Mo0.75Ge0.25 thin -films. Fabricated devices show a saturation of the internal detection efficiency at temperatures below 1 K, with system dark count rates below 500 counts per second over most of the bias range. Operation in a GM cryocooler at 2.5 K is possible with system detection efficiencies (SDE) exceeding 20% for SNSPDs which are not embedded inside of an optical stack to enhance absorption.