Low-excess-noise quinary AlGaInAsSb avalanche photodiodes on InP

Quinary AlGaInAsSb avalanche photodiodes (APDs), lattice-matched to InP, were demonstrated as low-noise multiplication layers. A 995 nm thick p-i-n Al0.85Ga0.07In0.08As0.63Sb0.37 structure was grown on InP as a random alloy by molecular beam epitaxy. The devices exhibited breakdown at approximately −58 V, corresponding to a peak electric field of 628.8 kV/cm. Under 450 nm illumination, a maximum gain of 842 was achieved near breakdown with pure electron injection. Excess-noise measurements across multiple devices showed F(M) values that were reproducibly low and deviated from the McIntyre local-field prediction, remaining below those of comparable Al0.85Ga0.15As0.56Sb0.44 and Al0.79In0.21As0.74Sb0.26 APDs at moderate and high gain. At M ≈ 70, the effective k of AlGaInAsSb is approximately 0.01, compared with approximately ∼0.022 and ∼0.037 for AlGaAsSb and AlInAsSb, respectively. These results identify AlGaInAsSb as a promising quinary multiplication material for next-generation low-noise InP-based APDs and for potential application toward linear-mode single-photon detectors.