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Extended Tight‐Binding and Thermochemical Modeling of III‐Nitride Heterostructures at Any Temperature and Pressure
Author(s) -
Ünlü H.
Publication year - 1999
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/(sici)1521-3951(199911)216:1<107::aid-pssb107>3.0.co;2-3
Subject(s) - semiconductor , tight binding , valence (chemistry) , atomic orbital , heterojunction , condensed matter physics , chemistry , band gap , atomic physics , binding energy , nitride , electron , materials science , electronic structure , computational chemistry , physics , quantum mechanics , organic chemistry , optoelectronics , layer (electronics)
An extended tight‐binding thermochemical model is proposed to determine the band offsets of group III‐nitride heterostructures as a function of temperature, pressure, and strain. The valence and conduction band energies of semiconductors at 0 K are first obtained using tight‐binding model, with the Hartree‐Fock atomic term values and considering the nonorthogonality of p‐orbitals of adjacent atoms and atomic spin–orbit splittings of p‐orbitals. Temperature, strain, and pressure effects on conduction and valence band energies are then determined using the thermochemical model which considers the free electrons (e — ) and free holes (e + ) as weakly interacting quasichemical particles in intrinsic semiconductors. Finally, the valence band offsets are determined by taking the difference between the valence band energies of constituent semiconductors which are screened by optical dielectric constants at any temperature, pressure, and strain. Excellent agreement is found between the theory and experiment.