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Tight‐Binding Calculation: Electronic Structure of (BeSe) n /(Si 2 ) m Superlattices
Author(s) -
Zhu Liqiang,
Wang E. G.,
Zhang Liyuan
Publication year - 1997
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(199712)204:2<643::aid-pssb643>3.0.co;2-p
Subject(s) - superlattice , condensed matter physics , band gap , valence band , electronic band structure , tight binding , conduction band , offset (computer science) , band offset , materials science , discontinuity (linguistics) , electronic structure , physics , quantum mechanics , electron , computer science , mathematical analysis , mathematics , programming language
In a semiempirical sp 3 s* tight‐binding scheme, bulk parameters for BeSe are determined by fitting the first‐principles calculation and the detailed calculations of electronic structure of the (BeSe) n /(Si 2 ) m (110) superlattices are performed within a wide range of n , m ≤ 20. It is found that the fundamental energy gap increases (up to 2.11 eV at the X˜ point for n = m = 2) with decreasing superlattice period and the Si layer plays an important role in determining the fundamental energy gap of the superlattice system due to spatial quantum confinement effects. For all reasonable values (ranging from 0 to 3.5 eV) of the valence‐band discontinuity used in the calculation, there is an empty interface band in the thermal gap of the (BeSe) n /(Si 2 ) m (110) ( n , m ≤ 20) system and the conduction band minima shift from X to Γ along Γ‐X‐ while increasing the band offset, but they never reach the Γ point.