Epitaxial indium antimonide for multiband photodetection from IR to millimeter/terahertz wave

Abstract

Conventional photodetection converts light into electrical signals only in a single electromagnetic waveband. Multiband detection technology is highly desirable because it can handle multispectral information discrimination, identification, and processing. Current epitaxial solid-state multiband detection technologies are mainly within the IR wave range. Here, we report epitaxial indium antimonide on gallium arsenide for IR and millimeter/terahertz wave multiband photodetection. The photoresponse originates from interband transition in optoelectrical semiconductors for IR wave, and surface plasmon polaritons induced nonequilibrium electrons for a millimeter/terahertz wave. The detector shows a strong response for an IR wave with a cutoff wavelength of 6.85 μm and a blackbody detectivity of 1.8 × 109 Jones at room temperature. For a millimeter/terahertz wave, the detector demonstrates broadband detection from 0.032 THz (9.4 mm) to 0.330 THz (0.9 mm); that is, from Ka to the W and G bands, with a noise equivalent power of 1.0 × 10−13 W Hz−1∕2 at 0.270 THz (1.1 mm) at room temperature. The detection performance is an order of magnitude better while decreasing the temperature to 170 K, the thermoelectric cooling level. Such detectors, capable of large scale and low cost, are promising for advanced uncooled multiband detection and imaging systems.