Mid-wavelength infrared type-II InAs/GaSb superlattice interband cascade photodetectors

Abstract

Recently, a new strategy to achieve high-operating temperature (HOT) infrared photodetectors to include cascade devices and alternate materials such as type-II superlattices has been observed. Another method to reduce dark current is related to the limitation of the volume of detector material via a concept of a photon-trapping detector. The performance of an innovative HOT detector designing so-called interband (IB) cascade type-II MWIR InAs/GaSb superlattice detectors is presented. Detailed analysis of the detector’s performance (such as dark current, RA product, current responsivity, and response time) versus bias voltage and operating temperatures (220 to 400 K) is performed, pointing out the optimal working conditions. At the present stage of technology, the experimentally measured R0A values of the IB cascade type-II superlattice detectors at room temperature are higher than those predicted for HgCdTe photodiodes. It is shown that these HOT detectors have emerged as the competitors of HgCdTe photodetectors.