InGaAlAs-InP quantum-well infrared photodetectors for 8-20-/spl mu/m wavelengths

摘要

We demonstrate the first long-wavelength quantum-well infrared photodetectors using the lattice-matched n-doped InGaAlAs-InP materials system. Samples with AlAs mole fractions of 0.0, 0.1, and 0.15 result in cutoff wavelengths of 8.5, 13.3, and 19.4 /spl mu/m, respectively, a 45/spl deg/ facet coupled illumination responsivity of R=0.37 /spl mu/m and detectivity of D/sub /spl lambda//*=3/spl times/10/sup 8/ cm/spl middot//spl radic/(Hz)/spl middot/ at T=77 K, for a cutoff wavelength /spl lambda//sub c/=13.3 /spl mu/m have been achieved. Based on the measured intersubband photoresponse wavelength, a null conduction band offset is expected for In/sub 0.52/Ga/sub 0.21/Al/sub 0.27/As-InP heterojunctions.