Anomalous band-gap bowing of AlN1-xPx alloy

JOURNAL OF ALLOYS AND COMPOUNDS

卷:575

Article

Winiarski, M. J.¹  Polak, M.²  Scharoch, P.² 

[1] Polish Acad Sci, Inst Low Temp & Struct Res, PL-50422 Wroclaw, Poland

[2] Wroclaw Univ Technol, Inst Phys, PL-50370 Wroclaw, Poland

关键词: Semiconductors;    Nitride materials;    Electronic band structure;   

DOI  :  10.1016/j.jallcom.2013.03.269

来源: Elsevier

【 摘 要 】

Electronic structure of zinc blende AlN1-xPx alloy has been calculated from first principles. Structural optimization has been performed within the framework of LDA and the band-gaps calculated with the modified Becke-Jonson (MBJLDA) method. Two approaches have been examined: the virtual crystal approximation (VCA) and the supercell-based calculations (SC). The composition dependence of the lattice parameter obtained from the SC obeys Vegard's law whereas the volume optimization in the VCA leads to an anomalous bowing of the lattice constant. A strong correlation between the band-gaps and the structural parameter in the VCA method has been observed. On the other hand, in the SC method the supercell size and atoms arrangement (clustered vs. uniform) appear to have a great influence on the computed band-gaps. In particular, an anomalously big band-gap bowing has been found in the case of a clustered configuration with relaxed geometry. Based on the performed tests and obtained results some general features of MBJLDA are discussed and its performance for similar systems predicted. (c) 2013 Elsevier B.V. All rights reserved.

【 授权许可】

Free