ROOM-TEMPERATURE CHARACTERIZATION OF INGAAS/ALAS MULTIPLE-QUANTUM-WELL P-I-N-DIODES

We report the growth and fabrication of strained InxGa 1-xAs/AlAs multiple quantum well p-i-n diodes, where 5.6%<x<15.3%. Characterization via high-resolution x-ray diffraction shows that for the higher indium composition, partial relaxation of the strain has occurred. Using photocurrent spectroscopy, we demonstrate that all the samples studied (whether partially relaxed or not) show (i) strong room-temperature excitonic features and (ii) under an applied electric field, a strong quantum confined Stark effect with retention of clearly resolvable excitons for fields up to ≊300 kV/cm. Both these results can be attributed to the substantial confining potential caused by our use of AlAs barriers. The results demonstrate that the system has potential use for the production of optical modulators. © 1994 American Institute of Physics.