Band-to-Band Transitions in InAs/GaSb Multi-Quantum-Well Structures Using k.p Theory: Effects of Well/Barrier Width and Temperature

Abstract

We investigated the conduction- and valence-confined energy levels and first band-to-band transition energies of a type-II InAs/GaSb multi-quantum-well at 77 K and room temperature for various well and barrier thicknesses. We calculated the electron and hole confined energies based on Kane’s eight-band k.p formalism. We also explored the effect of the barrier width on the wells’ interactions, which was negligible for wells with a width wider than 30 nm. Moreover, we proposed a single exponential function to predict the first transition energies without considering the complex approach of k.p theory. Then, we measured the photoluminescence spectra of the manufactured samples, including thin wells (1, 2, and 3 monolayers) and wide barriers (50 nm). Finally, we made comparisons between the theoretical band-to-band transition energies for kz=0 and experimental results from the photoluminescence spectra for different well thicknesses at 77 and 300 K.

Keywords

• InAs/GaSb multi-quantum-well structure
• eight-band k.p theory
• finite difference method
• first transition energy
• photoluminescence