Lightly doped In0.53Ga0.47As/InP SWIR photodetectors with diffusion barrier structure

•A 200 nm thick moderately doped (5 × 1016 cm − 3) InGaAs layer was introduced in the interface of lightly doped InGaAs absorption layer (<1 × 1015 cm − 3) and InP cap layer, namely diffusion barrier structure.•Bulk lifetime measurements demonstrated that the material quality of the diffusion barrier structure maintained the same level of the typical structure.•SEM and SCM test results showed that the diffusion barrier structure effectively tailored the Zinc diffusion front with reduced depth.•Electrical measurements showed that PDs with the diffusion barrier structure exhibited a significantly lower dark current as well as an approximately three times higher peak detectivity, while the capacitance was only a few percent higher.