Pressure coefficients of band gaps of diamond

Journal Article · Wed Apr 15 04:00:00 EDT 1987 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.35.5856· OSTI ID:5816166

Fahy, S; Chang, K J; Louie, S G; Cohen, M L

Ab initio pseudopotential calculations of the pressure dependence of the direct and indirect band gaps in diamond using a plane-wave and a local-orbital method are presented. The pressure derivative of the fundamental gap is found to be positive, in contrast with the negative derivative usually observed near the X point in the diamond- and zinc-blende-structure semiconductors. Its value is found to be 0.53 meV/kbar for the local-orbital method and 0.58 meV/kbar for the plane-wave method, as compared to the measured value of 0.5 meV/kbar. The anomalous sign of the pressure derivative of the fundamental gap is understood in terms of the absence of d states with the same principal quantum number as the low-lying s and p valence states of the carbon atom.

• Research Organization: Department of Physics, University of California, Berkeley, California 94720; Materials and Molecular Research Division, Lawrence Berkeley Laboratory, Berkeley, California 94720
• OSTI ID: 5816166
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 35:11; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
CARBON
D STATES
DIAMONDS
ELEMENTAL MINERALS
ELEMENTS
ENERGY GAP
ENERGY LEVELS
MATERIALS
MINERALS
NONMETALS
PRESSURE DEPENDENCE
SEMICONDUCTOR MATERIALS
VERY HIGH PRESSURE