Self-assembly of ordered wurtzite/rock salt heterostructures-A new view on phase separation in MgxZn1-xO

被引：4
作者：
Gries, K. I. [1 ,2 ]
Wassner, T. A. [3 ]
Vogel, S. [1 ,2 ]
Bruckbauer, J. [3 ]
Haeusler, I. [4 ]
Straubinger, R. [1 ,2 ]
Beyer, A. [1 ,2 ]
Chernikov, A. [1 ,2 ]
Laumer, B. [3 ,5 ,6 ]
Kracht, M. [5 ,6 ]
Heiliger, C. [5 ,6 ]
Janek, J. [6 ,7 ]
Chatterjee, S. [1 ,2 ]
Volz, K. [1 ,2 ]
Eickhoff, M. [5 ,6 ]
机构：
[1] Univ Marburg, Fac Phys, D-35032 Marburg, Germany
[2] Univ Marburg, Ctr Mat Sci, D-35032 Marburg, Germany
[3] Tech Univ Munich, Walter Schottky Inst, D-85748 Garching, Germany
[4] Humboldt Univ, Inst Phys, D-12489 Berlin, Germany
[5] Univ Giessen, Inst Phys 1, D-35392 Giessen, Germany
[6] Univ Giessen, Lab Mat Forsch LaMa, D-35392 Giessen, Germany
[7] Univ Giessen, Inst Phys Chem, D-35392 Giessen, Germany
来源：
JOURNAL OF APPLIED PHYSICS | 2015年 / 118卷 / 04期
关键词：
MOLECULAR-BEAM EPITAXY; SPINODAL DECOMPOSITION; BUFFER LAYER; MGO BUFFER; ZNO; FILMS; STABILITY; EPILAYERS; SYSTEM; ALLOYS;
D O I：
10.1063/1.4926776
中图分类号：
O59 [应用物理学];
学科分类号：
摘要：
The self-assembled formation of ordered, vertically stacked rocksalt/wurtzite MgxZn1-xO heterostructures by planar phase separation is shown. These heterostructures form quasi "natural" two-dimensional hetero-interfaces between the different phases upon annealing of MgO-oversaturated wurtzite MgxZn1-xO layers grown by plasma-assisted molecular beam epitaxy on c-plane sapphire substrates. The optical absorption spectra show a red shift simultaneous with the appearance of a cubic phase upon annealing at temperatures between 900 degrees C and 1000 degrees C. Transmission electron microscopy reveals that these effects are caused by phase separation leading to the formation of a vertically ordered rock salt/wurtzite heterostructures. To explain these observations, we suggest a phase separation epitaxy model that considers this process being initiated by the formation of a cubic (Mg,Zn) Al2O4 spinel layer at the interface to the sapphire substrate, acting as a planar seed for the epitaxial precipitation of rock salt MgxZn1-xO. The equilibrium fraction x of magnesium in the resulting wurtzite (rock salt) layers is approximately 0.15 (0.85), independent of the MgO content of the as-grown layer and determined by the annealing temperature. This model is confirmed by photoluminescence analysis of the resulting layer systems after different annealing temperatures. In addition, we show that the thermal annealing process results in a significant reduction in the density of edge-and screw-type dislocations, providing the possibility to fabricate high quality templates for quasi-homoepitaxial growth. (C) 2015 AIP Publishing LLC.
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页数：8
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共 33 条
  • [1] Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer
    Bakin, A.
    Kioseoglou, J.
    Pecz, B.
    El-Shaer, A.
    Mofor, A. -C.
    Stoemenos, J.
    Waag, A.
    [J]. JOURNAL OF CRYSTAL GROWTH, 2007, 308 (02) : 314 - 320
  • [2] FREE ENERGY OF A NONUNIFORM SYSTEM .3. NUCLEATION IN A 2-COMPONENT INCOMPRESSIBLE FLUID
    CAHN, JW
    HILLIARD, JE
    [J]. JOURNAL OF CHEMICAL PHYSICS, 1959, 31 (03) : 688 - 699
  • [3] INVESTIGATIONS OF DISLOCATION STRAIN FIELDS USING WEAK BEAMS
    COCKAYNE, DJ
    RAY, ILF
    WHELAN, MJ
    [J]. PHILOSOPHICAL MAGAZINE, 1969, 20 (168): : 1265 - &
  • [4] Influence of surface diffusion on the formation of hollow nanostructures induced by the Kirkendall effect: The basic concept
    Fan, Hong Jin
    Knez, Mato
    Scholz, Roland
    Hesse, Dietrich
    Nielsch, Kornelius
    Zacharias, Margit
    Gosele, Ulrich
    [J]. NANO LETTERS, 2007, 7 (04) : 993 - 997
  • [5] Molecular beam epitaxy of MgxZn1-xO layers without wurzite-rocksalt phase mixing from x=0 to 1 as an effect of ZnO buffer layer
    Fujita, S
    Takagi, T
    Tanaka, H
    Fujita, S
    [J]. PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, 2004, 241 (03): : 599 - 602
  • [6] ZnMgO epilayers and ZnO-ZnMgO quantum wells for optoelectronic applications in the blue and UV spectral region
    Gruber, T
    Kirchner, C
    Kling, R
    Reuss, F
    Waag, A
    [J]. APPLIED PHYSICS LETTERS, 2004, 84 (26) : 5359 - 5361
  • [7] COLUMN APPROXIMATION EFFECTS IN HIGH RESOLUTION ELECTRON MICROSCOPY USING WEAK DIFFRACTED BEAMS
    HOWIE, A
    SWORN, CH
    [J]. PHILOSOPHICAL MAGAZINE, 1970, 22 (178): : 861 - &
  • [8] ON SPINODAL DECOMPOSITION IN ELASTICALLY ANISOTROPIC EPITAXIAL-FILMS OF III-V SEMICONDUCTOR ALLOYS
    IPATOVA, IP
    MALYSHKIN, VG
    SHCHUKIN, VA
    [J]. JOURNAL OF APPLIED PHYSICS, 1993, 74 (12) : 7198 - 7210
  • [9] Effect of post annealing on the band gap of MgxZn1-xO thin films
    Jiang, D. Y.
    Shen, D. Z.
    Liu, K. W.
    Shan, C. X.
    Zhao, Y. M.
    Yang, T.
    Yao, B.
    Lu, Y. M.
    Zhang, J. Y.
    [J]. SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 2008, 23 (03)
  • [10] Phase stability of cubic Mg0.55Zn0.45O thin film studied by continuous thermal annealing method
    Ju, Z. G.
    Shan, C. X.
    Yang, C. L.
    Zhang, J. Y.
    Yao, B.
    Zhao, D. X.
    Shen, D. Z.
    Fan, X. W.
    [J]. APPLIED PHYSICS LETTERS, 2009, 94 (10)
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