QUANTUM-WELL GAAS/ALGAAS SHALLOW-DONOR FAR-INFRARED PHOTOCONDUCTORS GROWN BY MOLECULAR-BEAM EPITAXY

Photoconductors utilizing planar-doped silicon shallow donors in GaAs quantum wells formed with AlGaAs barriers have been fabricated and measured to have far-infrared (FIR) resonant-wavelength responsivities of approximately 1 V W-1, with noise equivalent power values of approximately 1 X 10(-7) W Hz-1/2 at 4 K. The technology makes possible the use of FIR photoconductive magnetospectroscopy to measure the well position of sheet-doped silicon ions when incorporated at doping levels below 1 X 10(16) CM-3. A comparison of the measured position of the ions with the intended position reveals a discrepancy that can be linked to the growth parameters used to produce the structure.