Photodetector Devices Based on p–i–n and Barrier Structures of the Mid-Wave IR Spectrum Range

Abstract

Multilayer structures based on semiconductor materials of the antimonide group with InSb and Al_xIn_1 – xSb absorbing layers, including structures with an InAlSb barrier layer (InSb/InAlSb/InSb), designed for the manufacturing of advanced photodetectors (PDs) that detect radiation in the mid-wave infrared (IR) range. On the basis of p–i–n and barrier structures grown by the MBE method, photosensitive elements (PSEs) of various topologies with InSb and Al_xIn_1 – xSb absorbing layers were fabricated. It is shown that wide-gap Al_xIn_1 – xSb ternary solutions, which detect radiation in the medium-wavelength region of the spectrum, are an alternative to the narrow-gap binary compound InSb, because, due to the wide-gap, photodiodes based on Al_xIn_1 – xSb have lower currents and, therefore, noise. The average values of detectivity D* and noise-equivalent temperature difference (NETD) have been measured for various topology photodetectors, so D* was more than 10¹¹ cm W^–1 Hz^1/2 in p–i–n structures, and D* exceed of 10¹² cm W^–1 Hz^1/2 in barrier structures.