Theoretical Study on Effect of Interfacial Properties on Optical Properties of InAs/GaSb Type Ⅱ Superlattices
The InAs/GaSb type-Ⅱ superlattice(SL)constitutes the fundamental structure for mid-infrared opto-electronic devices,characterized by its type-Ⅱ band alignment that facilitates the spatial separation of electrons and holes across the interface,and a unique atomic configuration leading to a rich variety of interface states.Building up-on the Burt-Foreman envelope function theory,we investigate the influence of different interface states on the elec-tronic states and wave functions of the superlattice.Theoretical calculations indicate that both asymmetric distribu-tions of interface states,namely gradual interface variation and interface potential,result in spin splitting of the heavy-hole band,while spin splitting in the light-hole band occurs only with the application of an interface potential.Additionally,we examine the trends in the band gap of the superlattice system when altering well width and barrier height.The results show that as the barrier thickness increases,the gap calculations under both abrupt and gradual interface states gradually decrease,converging with increasing thickness.In contrast,the gap calculated with inter-face potential treatment increases with the thickness of the barrier,exhibiting an opposite trend to the former two.This provides a theoretical foundation for the precise design of mid-infrared superlattice devices.
antimonidesuperlatticeinterface stateforward and backward difference method
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