RESUMEN
The electron and hole avalanche multiplication characteristics have been measured in bulk AlAs0.56Sb0.44 p-i-n and n-i-p homojunction diodes, lattice matched to InP, with nominal avalanche region thicknesses of ~0.6 µm, 1.0 µm and 1.5 µm. From these and data from two much thinner devices, the bulk electron and hole impact ionization coefficients (α and ß respectively), have been determined over an electric-field range from 220-1250 kV/cm for α and from 360-1250 kV/cm for ß for the first time. The α/ß ratio is found to vary from 1000 to 2 over this field range, making it the first report of a wide band-gap III-V semiconductor with ionization coefficient ratios similar to or larger than that observed in silicon.
RESUMEN
The optical properties of In0.3Ga0.7As/GaAs surface quantum dots (SQDs) and buried QDs (BQDs) are investigated by photoluminescence (PL) measurements. The integrated PL intensity, linewidth, and lifetime of SQDs are significantly different from the BQDs both at room temperature and at low temperature. The differences in PL response, measured at both steady state and in transient, are attributed to carrier transfer between the surface states and the SQDs.
