P-type quantum well infrared photodetectors covering wide spectrum

Using a set of p-type GaAs/AlGaAs quantum well infrared photodetectors, a wide spectral coverage is demonstrated. Photoresponses at wavelengths as short as 1.4 /spl mu/m and as long as 15 /spl mu/m are shown. The shortest wavelength device with a high Al fraction (95%) peaks at 1.9 /spl mu/m and covers a range of 1.4 to 3 /spl mu/m.