ALUMINUM FREE GAINP GAAS QUANTUM-WELL INFRARED PHOTODETECTORS FOR LONG-WAVELENGTH DETECTION/

We demonstrate quantum well infrared photodetectors based on a GaAs/Ga 0.51In0.49P superlattice structure grown by gas-source molecular beam epitaxy. Wafers were grown with varying well widths. Wells of 40, 65, and 75 Angstrom resulted in peak detection wavelengths of 10.4, 12.8, and 13.3 mu m with a cutoff wavelength of 13.5, 15, and 15.5 mu m, res pectively. The measured peak and cutoff wavelengths match those predic ted by eight band theoretical analysis. Measured dark currents were lo wer than equivalent GaAs/AlGaAs samples. (C) 1997 American Institute o f Physics.