Improved III-V Antimonide-Based Superlattice Materials From Growth and Defect Modeling

Absorber layers based on Type-II superlattices (T2SLs) composed of III-V compound semiconductors (e.g. InAs and InSb) are a promising sensor technology for infrared imaging; however, carrier lifetimes are often significantly shorter than expected, particularly in InAs/InAsSb LWIR T2SL designs that should provide high carrier lifetimes. There is strong evidence that the short lifetime results from Shockley-Read-Hall defects that are inactive in the bulk constituents. A combination of quantum mechanical calculations and molecular dynamics-based epitaxial growth simulations will be used to optimize T2SL growth strategies to maximize SRH lifetime. The most promising strategies identified from the simulation results will be tested by experiments that will assess the theoretical understanding and optimize a growth process based on the predictions. Technology transfer to a commercial T2SL material foundry will also take place.