Strain compensated In/sub 1-x/Ga/sub x/As (x<0.47) quantum well photodiodes for extended wavelength operation

The use of highly strained (-1.8%) InGaAs quantum wells for the detection of optical radiation beyond the InP lattice-matched bandgap of 1.65 /spl mu/m wavelength is reported. Excellent crystal quality for up to 50 quantum wells is maintained through strain compensation using tensile InGaP. Transmission electron microscopy and double crystal X-ray diffraction reveal smooth interfaces and no observable defects for In/sub 0.83/Ga/sub 0.17/As layers with widths less than 80 /spl Aring/. Single-pass quantum efficiencies of 33% have been achieved at 1.95 /spl mu/m wavelength using a 50 period, strain compensated p-i-n multiple-quantum well structure in a top illuminated mesa device.