InP-Based Avalanche Photodiodes with ≫ 2.1μm Detection Capability

Type-II superlattice formed by In
_0.53
Ga
_0.47
As/GaAs
_0.51
Sb
_0.49
wafers have been grown on InP substrates. The superlattice is studied in several aspects to explore its potential in achieving ≫2.1μm detection InP-based avalanche photodiodes. The ionisation coefficients of the superlattice In
_0.53
Ga
_0.47
As(5nm) /GaAs
_0.47
Sb
_0.49
(5nm) are found to be similar to those of In
_0.53
Ga
_0.47
As. Hence the more compatible avalanche material is InAlAs for low excess noise performance. In addition photoluminescence data indicated that the detection wavelength of these superlattice can be longer by modifying the superlattice combination, while maintaining lattice-matched to InP.