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Full-Text Articles in Physical Sciences and Mathematics
Direct Enumeration Of Alloy Configurations For Electronic Structural Properties, Gus L. W. Hart, Peter A. Graf, Kwiseon Kim, Wesley B. Jones
Direct Enumeration Of Alloy Configurations For Electronic Structural Properties, Gus L. W. Hart, Peter A. Graf, Kwiseon Kim, Wesley B. Jones
Faculty Publications
We present and apply an approach to directly enumerate the band gaps and effective masses of all possible zinc blende-based alloy configurations whose unit cell contains up to a specified number of atoms. This method allows us to map the space of band gaps and effective masses versus alloy composition and atomic configuration. We demonstrate that a large number of band gaps and effective masses are available. We also discuss convergence of the method with respect to unit cell size and the combined optimization of band gap and effective mass for AlGaAs and GaInP semiconductor alloys.
Boron Alloying In Gan, Gus L. W. Hart, Laurian Escalanti
Boron Alloying In Gan, Gus L. W. Hart, Laurian Escalanti
Faculty Publications
Using first-principles calculations in the local density approximation, we studied effects of adding up to 6% boron to zinc-blende GaN. We found that the band gap increases monotonically with boron incorporation, in agreement with experiment. A composition-independent band-gap bowing parameter of 4.30 eV was determined, and proved to be large compared to bowing for other mixed cation systems. The formation enthalpy of mixing, ΔH, was determined for BxGa1-xN, BxGa1-xAs, and GaAs1-xNx. A comparison of enthalpies indicates that the production of BxGa1-xN films with boron concentrations of at least 5% may be possible.
Electronic Structure Of Bas And Boride Iii-V Alloys, Gus L. W. Hart, Alex Zunger
Electronic Structure Of Bas And Boride Iii-V Alloys, Gus L. W. Hart, Alex Zunger
Faculty Publications
Boron arsenide, the typically ignored member of the Group-III–V arsenide series BAs-AlAs-GaAs-InAs is found to resemble silicon electronically: its Γ conduction-band minimum is p-like (Γ15), not s-like (Γ1c), it has an X1c-like indirect band gap, and its bond charge is distributed almost equally on the two atoms in the unit cell, exhibiting nearly perfect covalency. The reasons for these are tracked down to the anomalously low atomic p orbital energy in the boron and to the unusually strong s–s repulsion in BAs relative to most other Group-III–V compounds. We find unexpected valence-band offsets of BAs with respect to GaAs and …