The design and characteristics of a three-spectrum multielement photodetector device with a sensitivity range from 0.6 to 12.0 μ m, which consists of three arrays of photodetectors having sensitivity ranges 0.6–0.9, 3–5, and 8–12 μ m, are described. Methods of fabrication of photodetector arrays, the photodetector device as a whole, and its photoelectric characteristics are presented.