Effects of strain-induced electric fields on the electronic structure of (111) growth axis semiconductor superlattices
The presence of internal strains in (111) growth axis strained-layer semiconductor superlattices is responsible for the generation of polarization fields due to the piezoelectric effect. These fields do not occur in (100) growth axis superlattices because the orientation of the lattice-mismatch induced strains is such that they do not produce polarization fields in zinc blende materials. For III--V semiconductor superlattices grown along the (111) direction, the magnitude of these strain-induced electric fields can be of the order of 10/sup 5/ V/cm. We investigate the effects of the strain-induced electric fields on the electronic structure of Ga/sub 0.47/In/sub 0.53/As--Al/sub 0.70/In/sub 0.30/As strained-layer superlattices grown along the (111) direction. This system is characterized by a lattice mismatch of 1.5%. We demonstrate that the presence of strain-induced electric fields result in sizable Stark shifts on the superlattice electron and hole subbands. This energy shift increases with superlattice layer thickness. Moreover, the presence of these strain-induced electric fields modifies superlattice wave functions and causes a spatial separation of the electrons and the holes within the confining superlattice layers.
- Research Organization:
- Xerox Webster Research Center, Webster, New York 14580
- OSTI ID:
- 5534198
- Journal Information:
- J. Vac. Sci. Technol., B; (United States), Vol. 4:4
- Country of Publication:
- United States
- Language:
- English
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