GROWTH AND CHARACTERIZATION OF ALGAAS/GAAS QUANTUM-WELL STRUCTURES FOR THE FABRICATION OF LONG WAVELENGTH INFRARED DETECTORS

Infrared detectors based on AlGaAs/GaAs multi quantum wells operating close to background limitation have been fabricated by MOVPE. Since detector performance depends critically on quantum well parameters, a sensitive and preferably non-destructive characterization method is demanded for. X-ray diffraction corresponds to this criterion and may be utilized prior to detector processing. A characterization technique based on X-ray diffraction is compared with Fourier transform infrared spectroscopy and photoluminescence measurements and the consistency of these methods is thereby ascertained. Quantum well characteristics obtained in this manner are finally compared with actual detector performance.