We have used an eight-band model to investigate the electronic structures and to calculate the optical matrix elements of InAs-GaSb broken gap semiconductor heterostructures. The unusual hybridization of the conduction band states in the InAs layers with the valence band states in the GaSb layers has been analyzed in detail. We have studied the dependence of the optical matrix elements on the degree of conduction-valence hybridization, the tuning of the hybridization by varying the width of the GaSb layers and/or InAs layers, and the sensitivity of quantized levels to this tuning. Large spin-orbit splitting in the energy bands has been demonstrated. Our calculation can serve as a theoretical model for infrared lasers based on broken gap quantum well heterostructures.

• Received 4 October 1999

DOI:https://doi.org/10.1103/PhysRevB.61.16743