Dislocation reduction in AlInSb mid-infrared photodiodes grown on GaAs substrates

We investigated the electrical and optical properties of a highly mismatched AlInSb/GaAs photodiode sensor working in the mid-infrared range at room temperature. A substantial increase in the device performance was achieved by controlling the strain energy density in the dislocation filter layers and barrier layers to reduce the density of threading and interfacial dislocations, respectively. The resulting photodiode showed a high resistance-area product of 0.24 Ω cm² and a peak detectivity of 2.2 × 10⁹ cm Hz^1/2 W^-1 at 3.3 μm.