Electronic structure of (001)- and (111)-growth-axis semiconductor superlattices

Journal Article · Thu Jan 15 00:00:00 EST 1987 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.35.1242· OSTI ID:7045218

Mailhiot, C; Smith, D L

A kxp theory is used to investigate the electronic structure of semiconductor superlattices grown along the (001) and (111) axes. The present work considers the case of Ga/sub 1-//sub x/In/sub x/As-Al/sub 1-//sub y/In/sub y/As superlattices. We specifically treat three alloy composition pairs: a lattice-matched case (x = 0.53, y = 0.52), a case where the Ga-containing layers are in biaxial tension with a 0.8% lattice mismatch (x = 0.53, y = 0.64), and a case where the Ga-containing layers are in biaxial compression with a 1.5% lattice mismatch (x = 0.53, y = 0.30). We analyze the effects of the growth axis on the electronic structure of the superlattice from a consideration of the subband dispersion both parallel and perpendicular to the growth direction. Apart from point-group symmetry considerations, a major factor which differentiates the electronic structure of (001)- and (111)-growth-axis superlattices is the presence of large (exceeding 100 kV/cm) internal strain-induced electric fields in strained-layer superlattices grown along the (111) axis. These internal electric fields are directed along the (111) growth axis and are generated by the internal strain because the constituent semiconductors are piezoelectric. In (001)-growth-axis strained-layer superlattices, the orientation of the lattice-mismatch-induced strains is such that these fields are not present. We demonstrate that the strain-induced electric fields result in sizeable Stark shifts on the superlattice electron and hole subbands and lead to a substantial reduction of the superlattice band gap.

• Research Organization: Xerox Corporation, Webster Research Center (0114-41D), 800 Phillips Road, Webster, New York 14580
• OSTI ID: 7045218
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Vol. 35:3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ARSENIDES
ELECTRONIC STRUCTURE
GALLIUM ARSENIDES
INDIUM ARSENIDES
BAND THEORY
DISPERSION RELATIONS
ELECTRIC FIELDS
GROUP THEORY
PIEZOELECTRICITY
SCREENING
SEMICONDUCTOR MATERIALS
STARK EFFECT
STRAINS
SUPERLATTICES
SYMMETRY
WAVE FUNCTIONS
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
ELECTRICITY
FUNCTIONS
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
MATERIALS
MATHEMATICS
PNICTIDES
360603* - Materials- Properties