Mid-Infrared HgCdTe Heterostructure and Its Potential Application to APD Operation

Mid-wave infrared HgCdTe photodiode grown by metal-organic chemical vapor deposition was characterized for its use in avalanche operation. N
⁺
/N/p/P/P
⁺
/n
⁺
heterostructure meets the assumptions of the separated absorption and multiplication design. The p-type absorber, with an assumed Cd molar composition of 0.305, was optimized to operate up to
$4.4 ~\mu \text{m}$
at 230 K. The multiplication region is contained within the N layer with a wider energy gap (
$\text{x}_{\textit {Cd}}=0.33$
). Satisfactory gain of ~50 was achieved for a moderate reverse bias of −3.5 V and a temperature of 160 K.