Development and characterization of GaInAsSb and InAsSbP mid-infrared photodetectors

We report work on liquid-phase heteroepitaxy of lattice-matched GaInAsSb (Andreev et al, 1989; Mebarki et al, 1996; Li et al, 1995; Yakovlev et al, 1991) and InAsSbP (Yakovlev et al, 1991; Garnham et al, 1988; Tournie et al, 1990) on GaSb and InAs substrates for high performance, room temperature, mid-infrared detectors. These quaternary alloy systems provide room-temperature IR detectors adjustable over the 1.7 to 4.5 μm wavelength range. In this work, detectors with response out to 2.9 μm were demonstrated. With proper device design, both the cut-on and cut-off wavelengths can be tailored. A significant advantage of using quaternary systems over binary and ternary compounds is the ability to "tune" the bandgap while still providing lattice matched growth to the substrate material. Another advantage is that this detector structure has good detectivity at room temperature, while most commercially available detectors require cooling to liquid nitrogen temperatures. Photodetectors operating in the mid-IR range will have a variety of commercial applications in air pollution monitoring, industrial process control, automobile emission monitoring, and future lightwave communication systems using novel fiber materials.