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Ab initio investigation of CaO-ZnO alloys under high pressure.

ABSTRACT: Ca(x)Zn(1-x)O alloys are potential candidates to achieve wide band-gap, which might significantly promote the band gap engineering and heterojunction design. We performed a crystal structure search for CaO-ZnO system under pressure, using an ab initio evolutionary algorithm implemented in the USPEX code. Four stable ordered Ca(x)Zn(1-x)O structures are found in the pressure range of 8.7-60?GPa. We further constructed the pressure vs. composition phase diagram of CaO-ZnO alloys based on the detailed enthalpy calculations. With the increase in Ca concentration, the CaO-ZnO alloy first undergoes a hexagonal to monoclinic transition, and then transforms back to a hexagonal phase. At Above 9?GPa, there is no cubic structure in the alloys, in contrast to the insostructural components (B1-B1). The band gap of the Ca(x)Zn(1-x)O alloy shows an almost linear increase as a function of the Ca concentration. We also investigated the variation regularity of the band gap under pressure.

SUBMITTER: Sha X

PROVIDER: S-EPMC4505315 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature

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Ab initio investigation of CaO-ZnO alloys under high pressure.

Sha Xiaojing X Tian Fubo F Li Da D Duan Defang D Chu Binhua B Liu Yunxian Y Liu Bingbing B Cui Tian T

Scientific reports 20150717

Ca(x)Zn(1-x)O alloys are potential candidates to achieve wide band-gap, which might significantly promote the band gap engineering and heterojunction design. We performed a crystal structure search for CaO-ZnO system under pressure, using an ab initio evolutionary algorithm implemented in the USPEX code. Four stable ordered Ca(x)Zn(1-x)O structures are found in the pressure range of 8.7-60 GPa. We further constructed the pressure vs. composition phase diagram of CaO-ZnO alloys based on the detai ...[more]

PMID: 26183060

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