Thermodynamic Stability and Redistribution of Charges in Ternary AlGaN, InGaN, and InAlN Alloys

Journal Article · Wed Jun 15 04:00:00 EDT 2005 · Semiconductors

DOI:https://doi.org/10.1134/1.1944849· OSTI ID:20718984

Deibuk, V G; Voznyi, A V ^[1]

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1. Fed'kovich National University, ul. Kotsyubinskogo 2, Chernovtsy, 58012 (Ukraine)

A model of the delta lattice parameter is used to study the thermodynamics of AlGaN, InGaN, and InAlN alloys. The phase diagrams obtained indicate that Al{sub x}Ga{sub 1-x}N is stable in the entire range of x, whereas the miscibility gap corresponds to 0.2 < x < 0.69 for In{sub x}Ga{sub 1-x}N and to 0.16 < x < 0.7 for In{sub x}Al{sub 1-x}N at 1000 K. Biaxial stresses lower the critical temperature and narrow the miscibility gap. The charge-density distribution is analyzed using the pseudopotential method to obtain an approximation of 32-atom supercells. The results of the analysis show that the stability of these alloys is controlled by the competition between the destabilizing contribution of strains related to the mismatch between the lattice constants and a stabilizing charge exchange between various chemical bonds. Biaxial stress reduces the charge redistribution caused by strains and thus increases the stability of an alloy.

• OSTI ID: 20718984
• Journal Information: Semiconductors, Journal Name: Semiconductors Journal Issue: 6 Vol. 39; ISSN SMICES; ISSN 1063-7826
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CHARGE DENSITY
CHARGE EXCHANGE
CHEMICAL BONDS
CRITICAL TEMPERATURE
GALLIUM ALLOYS
INDIUM ALLOYS
LATTICE PARAMETERS
NITROGEN ADDITIONS
PHASE DIAGRAMS
SEMICONDUCTOR MATERIALS
SOLUBILITY
STABILITY
STRAINS
STRESSES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0400-1000 K
TERNARY ALLOY SYSTEMS
THERMODYNAMICS