Low noise AlInAsSb avalanche photodiodes on InP substrates for 1.55 µm infrared applications

Abstract

We report the noise characteristics of an AlInAsSb avalanche photodiode (APD) on an InP substrate. We observe low excess noise corresponding to an impact ionization coefficient ratio (k) of 0.012, and a dark current density of 55 μA/cm2 at a gain of 10 at room temperature. The performance of commercial APDs on InP substrates is limited by the excess noise and the performance of state of the art (SOA) APDs on InP substrates is limited by the dark current. The combination of low excess noise and low dark current of AlInAsSb leads to a significant performance improvement compared to commercial APDs and provides a potential candidate for low noise, SOA, commercial APDs for near-infrared applications. When combined in a separate absorber, charge and multiplication layer (SACM) architecture with an InGaAs absorption layer, the low noise characteristics of AlInAsSb point towards a superior InP substrate-based APD targeting 1.55 μm for applications such as optical communications and light detection and ranging (LiDAR).