High-operating temperature far-infrared Si:Ga blocked-impurity-band detectors

Abstract

Silicon-based blocked impurity band (BIB) detectors have become the preferred candidate for the astronomical observation field because of their excellent ability for far-infrared detection, easy integration with the readout circuit, and potential for large-scale preparation. We fabricate Si:Ga BIB far-infrared detectors by a molecular beam epitaxy technique with an impressive blackbody specific detectivity of 4.21 × 1011 cm Hz1/2 W−1 at 10 K and nearly uniform broadband response between 2.5 and 20  μm. A response mechanism with variable temperature is described minutely by the varying temperature optoelectronic characterization and theoretical calculation as well as energy band diagram. The substantial results indicate that the responsivity of the detector can steadily maintain up to 26 K for far-infrared. This paper not only increases the accessibility of BIB detectors' fabrication tools but also provides an approach of high-operating temperature far-infrared detectors for astronomy explorations.