The impact of extended defects on the generation and recombination lifetime in n type In.53Ga.47As

Abstract

The relationship between the threading dislocation density (TDD), the generation (τg) and recombination lifetime (τr) in relaxed n-type In.53Ga.47As is investigated for a series of p+n junction diodes, containing a TDD ranging from 105 to 1010 cm−2. The TDs are generated intentionally by lattice-misfit growth on semi-insulating (SI) InP and GaAs substrates. The lifetimes have been extracted from diode current–voltage (I–V) and photoluminescence (PL) analysis showing that TDDs affect their values above a density of about 1 × 107 cm−2 (τg,E ~ 0) and about 1 × 108 cm−2 (τr and τPL), which can be well-explained by the charged dislocation cylinder model. In addition, a detailed comparison between the results from deep level transient spectroscopy and from the diode characterization is performed, showing that the responsible G/R center shifts toward mid-gap in In.53Ga.47As and transfers from a native point defect (PD1) to a TD (E2/H1). Finally, the classical concept of generation lifetime and recombination lifetime in terms of dislocations is discussed based on the results.