Structural and photoelectric studies on double barrier quantum well infrared detectors

Abstract

GaAs-AlAs-GaAlAs double barrier quantum well (DBQW) structures are employed for making the 3-5 /spl mu/m photovoltaic infrared (IR) detectors with a peak detectivity of 5/spl times/10/sup 11/ cmHz/sup 1/2 //W at 80 K. Double crystal X-ray diffraction is combined with synchrotron radiation X-ray analysis to determine the exact thickness of GaAs, AlAs and GaAlAs sublayers. The interband photovoltaic (PV) spectra of the DBQW sample and the spectral response of the IR photocurrent of the devices are measured directly by the edge excitation method, providing information about the spatial separation processes of photogenerated carriers in the multiquantum wells and the distribution of built-in field in the active region.