Study of Minority Carrier Lifetimes in Very Long Wave Infrared Strained Layer InAs/GaInSb Superlattices (Postprint)
SANDIA NATIONAL LABS ALBUQUERQUE NM ALBUQUERQUE United States
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Significantly improved carrier lifetimes in very long wavelength infrared VLWIR InAsGaInSb superlattice SL absorbers are demonstrated by using time-resolved microwave reflectance TMR measurements. A nominal 47.0 InAs21.5 Ga0.75In0.25Sb SL structure that produces an approximately 25 m response at 10 K has a minority carrier lifetime of 140 20 ns at 18 K, which is an order-of-magnitude improvement compare to previously reported lifetime values for other VLWIR detector absorbers. This improvement is attributed to the strain-engineered ternary SL design, which offers a variety of epitaxial advantages and ultimately leads to the improvements in the minority carrier lifetime b mitigating defect-mediated Shockley-Read-Hall SRH recombination centers. By analyzing the temperature dependence of TMR decay data, the recombination mechanisms and trap states that currently limit the performance of this SL absorber are identified. The results show a general decrease in the long-decay lifetime component, which is dominated by SRH recombination at temperatures below 30 K, and by Auger recombination at temperatures above 45 K.
- Radiofrequency Wave Propagation
- Atomic and Molecular Physics and Spectroscopy