Properties of amorphous GaN from first-principles simulations

被引:26
作者
Cai, B. [1 ]
Drabold, D. A. [1 ]
机构
[1] Ohio Univ, Dept Phys & Astron, Athens, OH 45701 USA
基金
美国国家科学基金会;
关键词
ELECTRICAL-PROPERTIES; PSEUDOPOTENTIALS; MICROCRYSTALLINE; DEPOSITION; FILMS;
D O I
10.1103/PhysRevB.84.075216
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Amorphous GaN (a-GaN) models are obtained from first-principles simulations. We compare four a-GaN models generated by "melt-and-quench" and the computer alchemy method. We find that most atoms tend to be fourfold, and a chemically ordered continuous random network is the ideal structure for a-GaN albeit with some coordination defects. Where the electronic structure is concerned, the gap is predicted to be less than 1.0 eV, underestimated as usual by a density functional calculation. We observe a highly localized valence tail and a remarkably delocalized exponential conduction tail in all models generated. Based upon these results, we speculate on potential differences in n- and p-type doping. The structural origin of tail and defect states is discussed. The vibrational density of states and dielectric function are computed and seem consistent with experiment.
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页数:6
相关论文
共 35 条
[1]   Structural and optoelectronic properties of amorphous GaN thin films [J].
Al-Zouhbi, Abla ;
Al-Din, Nasser Saad .
OPTICAL REVIEW, 2008, 15 (05) :251-254
[2]   Electron-phonon coupling is large for localized states [J].
Atta-Fynn, R ;
Biswas, P ;
Drabold, DA .
PHYSICAL REVIEW B, 2004, 69 (24) :245204-1
[3]   Ion-assisted deposition of amorphous GaN: Raman and optical properties [J].
Bittar, A ;
Trodahl, HJ ;
Kemp, NT ;
Markwitz, A .
APPLIED PHYSICS LETTERS, 2001, 78 (05) :619-621
[4]   Building block modeling technique: Application to ternary chalcogenide glasses g-Ge2As4Se4 and g-AsGe0.8Se0.8 [J].
Cai, B. ;
Zhang, X. ;
Drabold, D. A. .
PHYSICAL REVIEW B, 2011, 83 (09)
[5]   Structural fingerprints of electronic change in the phase-change-material: Ge2Sb2Te5 [J].
Cai, B. ;
Drabold, D. A. ;
Elliott, S. R. .
APPLIED PHYSICS LETTERS, 2010, 97 (19)
[6]   Ab initio models of amorphous InN [J].
Cai, B. ;
Drabold, D. A. .
PHYSICAL REVIEW B, 2009, 79 (19)
[7]   ELECTRONIC-STRUCTURE APPROACH FOR COMPLEX SILICAS [J].
DEMKOV, AA ;
ORTEGA, J ;
SANKEY, OF ;
GRUMBACH, MP .
PHYSICAL REVIEW B, 1995, 52 (03) :1618-1630
[8]   Topics in the theory of amorphous materials [J].
Drabold, D. A. .
EUROPEAN PHYSICAL JOURNAL B, 2009, 68 (01) :1-21
[9]   REACTIVE SPUTTERING OF GALLIUM NITRIDE THIN-FILMS FOR GAAS MIS STRUCTURES [J].
HARIU, T ;
USUBA, T ;
ADACHI, H ;
SHIBATA, Y .
APPLIED PHYSICS LETTERS, 1978, 32 (04) :252-253
[10]  
Hassan Z, 1999, MATER RES SOC SYMP P, V536, P245