One-dimensional crystal growth enables the epitaxial integration of III-V compound semiconductors onto a silicon (Si) substrate despite significant lattice mismatch. Here, we report a short-wavelength infrared (SWIR, 1.4–3 μm) photodetector that employs InAs nanowires (NWs) grown on Si. The wafer-scale epitaxial InAs NWs form on the Si substrate without a metal catalyst or pattern assistance; thus, the growth is free of metal-atom-induced contaminations, and is also cost-effective. InAs NW arrays with an average height of 50 μm provide excellent anti-reflective and light trapping properties over a wide wavelength range. The photodetector exhibits a peak detectivity of 1.9 × 108  cm·Hz1/2/W for the SWIR band at 77 K and operates at temperatures as high as 220 K. The SWIR photodetector on the Si platform demonstrated in this study is promising for future low-cost optical sensors and Si photonics.

Extended long wavelength infrared detection with a miniband-type AlGaAs/GaAs superlattice structure is reported. The experimental response band of the detector is peaked near 14.5 μm in good agreement with the theoretical response, provided that electron-electron interactions are taken into account. The detector operates at a low bias voltage, which could lead to important advantages in application to IR focal plane arrays.

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This letter describes results of a modeling analysis of IR radiative efficiency for cascade-type quantum well emitter structures, and the angular dependence of spontaneous emission. The radiative decay rates are calculated for different IR wavelength ranges. Estimates of radiative efficiency indicate that the performance of these cascade mode devices in the long- and midwavelength infrared range can be comparable to or superior to that reported at far-infrared range. Based upon calculations of the angular dependence of IR emission, an etched surface grating structure is proposed which should lead to high effective coupling efficiencies.