Publications

Demonstration of long minority carrier lifetimes in very narrow bandgap ternary InAs/GaInSb superlattices

Haugan, H.J.; Brown, G.J.; Olson, B.V.; Kadlec, Emil A.; Kim, Jin K.; Shaner, Eric A.

Minority carrier lifetimes in very long wavelength infrared (VLWIR) InAs/GaInSb superlattices (SLs) are reported using time-resolved microwave reflectance measurements. A strain-balanced ternary SL absorber layer of 47.0Å InAs/21.5Å Ga0.75In0.25Sb, corresponding to a bandgap of ∼50meV, is found to have a minority carrier lifetime of 140±20ns at ∼18K. This lifetime is extraordinarily long, when compared to lifetime values previously reported for other VLWIR SL detector materials. This enhancement is attributed to the strain-engineered ternary design, which offers a variety of epitaxial advantages and ultimately leads to a reduction of defect-mediated recombination centers.