Characteristics of Al$_{x}$In 1−$_{x}$As $_{y}$Sb1− $_{y}$ (x:0.3−0.7) Avalanche Photodiodes

We report avalanche photodiodes fabricated from Al $_{x}$ In 1− $_{x}$ As $_{y}$ Sb 1− $_{y}$ wafers grown by molecular beam epitaxy using the digital alloy technique. A series of Al $_{x}$ In 1− $_{x}$ As $_{y}$ Sb 1− $_{y}$ ( x = 0.3, 0.4, 0.5, 0.6, 0.7) p-i-n structures have been grown on GaSb substrate. Dark current, avalanche multiplication, excess noise, and external quantum efficiencies have been characterized. Very low excess noise, as characterized by k ∼ 0.01–0.05, has been achieved.