Lifetime assessment of In${}_x$Ga${}_{1-x}$As n-type hetero-epitaxial layers

Herein, the carrier lifetime in ≈5 × 10${}^{16}$ cm${}^{-3}$ n-doped In${}_x$Ga${}_{1-x}$As layers is studied by diode current-voltage analysis and by time-resolved photoluminescence. Two sets of hetero-epitaxial layers are grown on semi-insulating InP or GaAs substrates. The first set corresponds with a constant In content p + n stack, while the second set has a fixed x = 0.53 for the n-layer, while containing various extended defect densities by using a strain relaxed buffer with different x. This results in threading dislocation densities (TDDs) between ≈10${}^5$ cm${}^{-2}$ and a few 10${}^9$ cm${}^{-2}$. It is shown that the overall trend of the recombination lifetime versus TDD can be described by a first-order model considering a finite recombination lifetime value inside a dislocation core of 1 nm. For the generation lifetime, a strong electric-field enhancement factor is found. Also, the residual strain in the n-layer has an impact. Overall, the safe limit for TDD depends on the type of application and on the operation conditions (reverse diode bias). (© 2022 Wiley‐VCH GmbH)