OPTICAL AND TRANSPORT-PROPERTIES OF PIEZOELECTRIC [LLL]-ORIENTED STRAINED GA1-XINXSB GASB QUANTUM-WELLS/

Magneto-optical and magnetotransport studies have been conducted on a series of strained single Ga1-xInxSb/GaSb quantum wells grown along [0 01], [111]A, and [111]B directions by metal organic chemical vapor dep osition. Both the interband transition energies and the two-dimensiona l carrier density show dramatic differences between the three orientat ions. Self-consistent calculations including the strain-induced piezoe lectric field and the effect of band bending have been performed for t he [111] structures. Results of the calculations agree very well with the observed dependences on indium content in the wells, well width, a nd cap thickness. The difference between [001] and [111] samples is du e mainly to the presence of the piezoelectric field in the latter. The surface pinning held which is different in both direction and magnitu de in the [111]A and [111]B structures contributes to the significant difference in these two orientations for cap thicknesses below 500 Ang strom.