InGaAsP heterostructure avalanche photodiodes with high avalanche gain

Distinct improvements in avalanche-gain and dark-current characteristics have been made in InGaAsP heterostructure APD’s. A planar-type p-n junction is formed in an InP window layer, separated from a light-absorbing InGaAsP layer. This APD structure has yielded an avalanche gain of 3000 and a dark-current density as low a 1 μA/cm2 at 0.5 Vb.