Effect of a current blocking barrier on a 2-6 μ m p-GaAs/AlGaAs heterojunction infrared detector

Abstract

We report the performance of a 30 period p-GaAs/AlxGa1-xAs heterojunction photovoltaic infrared detector, with graded barriers, operating in the 2-6 μm wavelength range. Implementation of a current blocking barrier increases the specific detectivity (D) under dark conditions by two orders of magnitude to ∼1.9 × 1011 Jones at 2.7 μm, at 77 K. Furthermore, at zero bias, the resistance-area product (R0A) attains a value of ∼7.2 × 108 Ω cm2, a five orders enhancement due to the current blocking barrier, with the responsivity reduced by only a factor.