Low excess noise AlxIn1-xAsySb1-y (x: 0.3∼0.7) avalanche photodiodes

We report avalanche photodiodes fabricated from a previously uncharacterized material system, Al
_x
In
_1-x
As
_y
Sb
_1-y
digital alloy. A series of Al
_x
In
_1-x
As
_y
Sb
_1-y
(x: 0.3~0.7) p-i-n avalanche photodiodes have been grown on GaSb substrate. Dark current characteristics, avalanche multiplication, external quantum efficiency, and excess noise are presented. Very low excess noise, corresponding to k = 0.03~0.05, has been observed.