Influence of carrier concentration on the minority carrier lifetime in mid-wavelength infrared InAs/InAsSb superlattices

• Minority carrier lifetimes (MCL) in InAs/InAsSb superlattices were studied.
• A decrease of the MCL with increasing carrier concentration was observed in superlattices with intermediate carrier concentration.
• Decreasing MCL was attributed to dominating radiative recombination in superlattices.
• Good correlation between the experimentally observed trend and the theoretically expected decrease of radiative lifetime was obtained.
• The correlation between carrier concentration and MCL partly explains the spread in reported MCL for InAs/InAsSb superlattices.

The influence of carrier concentration on the minority carrier lifetime was studied in mid-wavelength infrared InAs/InAsSb superlattices. A significant correlation between the carrier concentration and the minority carrier lifetime was observed, with lifetime decreasing from 3.6 μs to 1 μs when increasing the carrier concentration from 2 × 1015 cm−3 to 4.4 × 1015 cm−3. From temperature dependence studies of the minority carrier lifetime, radiative recombination has been identified as the main recombination mechanism in these superlattices. The radiative recombination rate increases with carrier concentration which is consistent with our observations.