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Electron Microscope Study of Strain in InGaN Quantum Wells in GaN Nanowires

Published online by Cambridge University Press:  31 January 2011

Roy Geiss
Affiliation:
[email protected], NIST, Boulder, Colorado, United States
Kris Bertness
Affiliation:
[email protected], NIST, Boulder, Colorado, United States
Alexana Roshko
Affiliation:
[email protected], NIST, Boulder, Colorado, United States
David Read
Affiliation:
[email protected], NIST, Boulder, Colorado, United States
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Abstract

Strains in GaN nanowires with InGaN quantum wells (QW) were measured from transmission electron microscope (TEM) images. The nanowires, all from a single growth run, are single crystals of the wurtzite structure that grow along the <0001> direction, and are approximately 1000 nm long and 60 nm to 130 nm wide with hexagonal cross-sections. The In concentration in the QWs ranges from 12 to 15 at %, as determined by energy dispersive spectroscopy in both the transmission and scanning electron microscopes. Fourier transform (FT) analyses of <0002> and <1100> lattice images of the QW region show a 4 to 10 % increase of the c-axis lattice spacing, across the full specimen width, and essentially no change in the a-axis value. The magnitude of the changes in the c-axis lattice spacing far exceeds values that would be expected by using a linear Vegard's law for GaN – InN with the measured In concentration. Therefore the increases are considered to represent tensile strains in the <0001> direction. Visual representations of the location and extent of the strained regions were produced by constructing inverse FT (IFT) images from selected regions in the FT covering the range of c-axis lattice parameters in and near the QW. The present strain values for InGaN QW in nanowires are larger than any found in the literature to date for other forms of InxGa1-xN (QW)/GaN.

Type
Research Article
Copyright
Copyright © Materials Research Society 2009

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References

[1] Monemar, B. III-V nitrides - important future electronic materials, Journal of Materials Science-Materials in Electronics 10 (4), 227254, 1999.Google Scholar
[2] Jain, S. C., Willander, M., Narayan, J., Van Overstraeten, R. III-nitrides: Growth, characterization, and properties, Journal of Applied Physics 87 (3), 9651006, 2000.Google Scholar
[3] Orton, J. W., Foxon, C. T. Group III nitride semiconductors for short wavelength light-emitting devices, Reports on Progress in Physics 61 (1), 175, 1998.Google Scholar
[4] Damilano, B., Grandjean, N., Dalmasso, S., Massies, J. Room-temperature blue-green emission from InGaN/GaN quantum dots made by strain-induced islanding growth, Applied Physics Letters 75 (24), 37513753, 1999.Google Scholar
[5] Smeeton, T. M., Kappers, M. J., Barnard, J. S., Vickers, M. E., Humphreys, C. J. Electron-beam-induced strain within InGaN quantum wells: False indium “cluster” detection in the transmission electron microscope, Applied Physics Letters 83 (26), 54195421, 2003.Google Scholar
[6] Bertness, K. A., Sanford, N. A., Barker, J. M., Schlager, J. B., Roshko, A., Davydov, A. V., Levin, I. Catalyst-free growth of GaN nanowires, Journal of Electronic Materials 35 (4), 576580, 2006.Google Scholar
[7] Bierwolf, R., Hohenstein, M., Phillipp, F., Brandt, O., Crook, G. E., Ploog, K. Direct Measurement of Local Lattice-Distortions in Strained Layer Structures by HREM, Ultramicroscopy 49 (1-4), 273285, 1993.Google Scholar
[8] Jouneau, P. H., Tardot, A., Feuillet, G., Mariette, H., Cibert, J. HREM Strain Measurement of Ultra-Thin ZnTe and MnTe Layers Grown in CdTe, Microscopy of Semiconducting Materials (134), 329332, 1993.Google Scholar
[9] Hytch, M. J., Snoeck, E., Kilaas, R. Quantitative measurement of displacement and strain fields from HREM micrographs, Ultramicroscopy 74 (3), 131146, 1998.Google Scholar
[10] Robertson, M. D., Corbett, J. M., Webb, J. B., Jagger, J., Currie, J. E. Elastic strain determination in semiconductor epitaxial layers by HREM, Micron 26 (6), 521537, 1995.Google Scholar
[11] Robins, L. H., Bertness, K. A., Barker, J. M., Sanford, N. A., Schlager, J. B. Optical and structural study of GaN nanowires grown by catalyst-free molecular beam epitaxy. I. Near-band-edge luminescence and strain effects, Journal of Applied Physics 101 (11), 2007.Google Scholar
[12] Commercial equipment, instruments, or materials are identified only in order to adequately specify certain experimental procedures. In no case does such identification imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the products identified are necessarily the best available for the purpose.Google Scholar
[13] Görgens, L., Ambacher, O., Stutzmann, M., Miskys, C., Scholz, F., Off, J. Characterization of InGaN thin films using high-resolution x-ray diffraction, Applied Physics Letters 76 (5), 577579, 2000.Google Scholar
[14] Wright, A. F.; Nelson, J. S. Consistent Structural-Properties for Aln, Gan, and Inn, Physical Review B 51 (12), 78667869, 1995.Google Scholar
[15] Lin, Y. S. Study of various strain energy distribution in InGaN/GaN multiple quantum wells, Journal of Materials Science 41 (10), 29532958, 2006.Google Scholar