PT Journal
AU Il’in, KS
   Milostnaya, II
   Verevkin, AA
   Gol’tsman, GN
   Gershenzon, EM
   Sobolewski, R
TI Ultimate quantum efficiency of a superconducting hot-electron photodetector
SO Appl. Phys. Lett.
JI Appl. Phys. Lett.
PY 1998
BP 3938
EP 3940
VL 73
IS 26
DI 10.1063/1.122942
DE NbN SSPD; SNSPD
AB The quantum efficiency and current and voltage responsivities of fast hot-electron photodetectors, fabricated from superconducting NbN thin films and biased in the resistive state, have been shown to reach values of 340, 220 A/W, and 4×104 V/W,respectively, for infrared radiation with a wavelength of 0.79 μm. The characteristics of the photodetectors are presented within the general model, based on relaxation processes in the nonequilibrium electron heating of a superconducting thin film. The observed, very high efficiency and sensitivity of the superconductor absorbing the photon are explained by the high multiplication rate of quasiparticles during the avalanche breaking of Cooper pairs.
ER