Tomic, S,O'Reilly, EP,Klar, PJ,Gruning, H,Heimbrodt, W,Chen, WMM,Buyanova, IA;

2004

April

Physical Review B

Influence of conduction-band nonparabolicity on electron confinement and effective mass in GaNxAs1-x/GaAs quantum wells

Validated

()

MOLECULAR-BEAM EPITAXY SEMICONDUCTOR-LASERS GAINNAS ALLOYS ABSORPTION GANAS/GAAS LUMINESCENCE TRANSITIONS PARAMETERS GAAS1-XNX PRESSURE

69

We derive an analytical model to describe the conduction-band states of GaNAs-based quantum well structures, including the band anticrossing effect between N resonant states and the conduction-band edge. The predictions of the model are compared to those obtained using a full ten-band k.p model based on the same set of parameters. Both methods are then tested by comparison with the experimentally determined ground- and excited-state interband transition energies of GaNxAs1-x quantum wells of different well widths and N composition x obtained at 300 K and under hydrostatic pressures up to 2.0 GPa. We show that the transition energies can be described by a consistent set of material parameters in all the samples studied, and present how the conduction to valence-band offset ratio varies strongly with x in GaNxAs1-x/GaAs quantum well structures. We conclude that the model presented can be used to predict the transition energies and electron subband structure of any GaNxAs1-x/GaAs quantum well with well width between 2 and 25 nm, and N composition x between 1 and 4%, although further work is still required to confirm the optimum choice for the variation of band offset ratio with composition.

ARTN 245305