Al0.8Ga0.2As Avalanche Photodiodes for Single-Photon Detection.

We report Al0.8Ga0.2As recessed-window single-photon avalanche photodiodes with high internal single-photon detection efficiency and low dark count probability. External quantum efficiency was increased by a factor of 2 at \lambda = 405 nm. Annealing in arsine with hydrogen carrier gas reduced the dark count probability by a factor of 100, to \sim 10^{-6} /gate with a \sim 5$ ns gate, at room temperature. The activation energies of primary carrier traps, which give rise to afterpulsing, are extracted in a temperature range from 150 to 200 K. [ABSTRACT FROM PUBLISHER]