Infrared Barrier Detectors with Metamorphic InAsSb Absorbers on GaAs Substrates

We investigate barrier detectors based on metamorphic InAsSb operating above 200 K. Different detectors structures covering IR range from 3 to 17 μm were MBE grown on GaAs substrates. Selected issues concerning the barrier detectors' structure designing, growth, processing and measurements were indicated. InAs 1-x Sb x exhibits a relatively strong dependence of Sb composition x on the lattice constant, therefore, the buffer layers were chosen individually for each waveband. Theoretical simulations by the APSYS numerical platform (Crosslight) support detectors' design and help to overcame the unwanted energetic barriers due to the valence band offset (VBO). SIMS profiles analysis let to compare actual MBE grown InAsSb detector architecture with the intentional design. Current-voltage and spectral characteristics measurements determined the quality of obtained detectors and allowed them to calculate their detectivity. The performance of developed InAsSb detectors was compared with the state-of-the-art MCT devices. Recent advances in InAsSb barrier detectors allowed their room temperature detectivities to achieve 5×10 9 , 2×10 9 and 2×10 7 cmHz 1/2 W -1 at SWIR, MWIR and LWIR spectral ranges respectively, confirming the importance of III-V materials in the IR industry.