Tunable Quantum-Well Infrared Detector

Infrared detectors (2-25 microns) have been a subject of much interest in recent years for defense and space exploration applications. Detectors built using II-VI compounds (for example, HgCdTe) have been investigated in depth, but suffer from the instability and nonuniformity of the materials, and from processing difficulties. Recently, quantum-well detectors using III-V compounds have been produced which demonstrate good detectivity in the 10 micron wavelength region 1,2. Their approach is based on inter-subband absorption in quantum-wells, or on confined-state to conduction-band transitions, and is limited to a fixed band of wavelengths for a given detector.