Direct growth of etch pit-free GaN crystals on few-layer graphene

We report high-quality GaN crystals grown directly on graphene layers without a buffer layer by metal–organic chemical vapour deposition. Photoluminescence and Raman spectra revealed that GaN crystals grown on graphene layers had mild strain as compared to those grown on sapphire and SiO2 substrates. Etch pits were not observed on the surface of GaN/graphene, in which threading dislocations were diminished inside the bulk. This is markedly different from GaN/sapphire, in which threading dislocations were present on GaN surfaces. This opens a new possibility that graphene with π electrons and hexagonal symmetry could be an ideal substrate for GaN crystal growth instead of expensive sapphire substrates.

[1]  G. Yi,et al.  Transferable GaN Layers Grown on ZnO-Coated Graphene Layers for Optoelectronic Devices , 2010, Science.

[2]  Wi Hyoung Lee,et al.  van der Waals epitaxy of InAs nanowires vertically aligned on single-layer graphene. , 2012, Nano letters.

[3]  Shuji Nakamura,et al.  The Roles of Structural Imperfections in InGaN-Based Blue Light-Emitting Diodes and Laser Diodes , 1998 .

[4]  M. Graef,et al.  Microstructural characterization of α‐GaN films grown on sapphire by organometallic vapor phase epitaxy , 1995 .

[5]  V. Bulović,et al.  Graphene cathode-based ZnO nanowire hybrid solar cells. , 2013, Nano letters.

[6]  G. Feuillet,et al.  Transmission electron microscopy structural characterisation of GaN layers grown on (0001) sapphire , 1997 .

[7]  James S. Speck,et al.  Structural evolution in epitaxial metalorganic chemical vapor deposition grown GaN films on sapphire , 1995 .

[8]  Toshio Ogino,et al.  Mechanism of Yellow Luminescence in GaN , 1980 .

[9]  Y. Gohda,et al.  Structural phase transition of graphene caused by GaN epitaxy , 2012 .

[10]  H. Morkoç,et al.  Comprehensive characterization of hydride VPE grown GaN layers and templates , 2001 .

[11]  E. Suh,et al.  Characteristics of GaN‐based light emitting diode grown on circular convex patterned sapphire substrate , 2009 .

[12]  H. Morkoç,et al.  Raman scattering and photoluminescence of Mg-doped GaN films grown by molecular beam epitaxy , 1997 .

[13]  I. Ferguson,et al.  MOCVD growth of GaN on Si(111) substrates using an ALD-grown Al2O3 interlayer , 2009 .

[14]  U. Mishra,et al.  Carbon doping of GaN with CBr4 in radio-frequency plasma-assisted molecular beam epitaxy , 2004 .

[15]  P. Vennégués,et al.  Microstructure of GaN epitaxial films at different stages of the growth process on sapphire (0 0 0 1) , 1997 .

[16]  H. Okumura,et al.  Raman scattering analysis of GaN with various dislocation densities , 2008 .

[17]  K. Kushida,et al.  Carbon doping by ion implantation and C2H6 gas in GaN: Rutherford backscattering/channeling, Raman scattering and photoluminescence studies , 2004 .

[18]  D. Bour,et al.  Nitride-based semiconductors for blue and green light-emitting devices , 1997, Nature.

[19]  James S. Speck,et al.  Defect structure of metal‐organic chemical vapor deposition‐grown epitaxial (0001) GaN/Al2O3 , 1996 .

[20]  S. Nakamura,et al.  Candela‐class high‐brightness InGaN/AlGaN double‐heterostructure blue‐light‐emitting diodes , 1994 .

[21]  Peng Chen,et al.  Micro-Raman investigation of strain in GaN and AlxGa1−xN/GaN heterostructures grown on Si(111) , 2002 .

[22]  E. C. Carr,et al.  CORRELATION OF CATHODOLUMINESCENCE INHOMOGENEITY WITH MICROSTRUCTURAL DEFECTS IN EPITAXIAL GAN GROWN BY METALORGANIC CHEMICAL-VAPOR DEPOSITION , 1997 .

[23]  Eun Sung Kim,et al.  Synthesis of Large‐Area Graphene Layers on Poly‐Nickel Substrate by Chemical Vapor Deposition: Wrinkle Formation , 2009 .

[24]  V. Narayanan,et al.  Origins of threading dislocations in GaN epitaxial layers grown on sapphire by metalorganic chemical vapor deposition , 2001 .

[25]  Eric Pop,et al.  In(x)Ga(1-x)As nanowire growth on graphene: van der Waals epitaxy induced phase segregation. , 2013, Nano letters.

[26]  D. Ivey,et al.  Preparation of metallized GaN/sapphire cross sections for TEM analysis using wedge polishing. , 2002, Micron.

[27]  Eun Sung Kim,et al.  Influence of copper morphology in forming nucleation seeds for graphene growth. , 2011, Nano letters.

[28]  G. Yi,et al.  Vertically aligned ZnO nanostructures grown on graphene layers , 2009 .

[29]  J. Gerlach,et al.  Carbon as an acceptor in cubic GaN/3C-SiC , 2011 .

[30]  S. Chua,et al.  Orders of magnitude reduction in dislocation density in GaN grown on Si (111) by nano lateral epitaxial overgrowth , 2008 .

[31]  Eun Sung Kim,et al.  Probing graphene grain boundaries with optical microscopy , 2012, Nature.

[32]  Rudin,et al.  Temperature-dependent exciton linewidths in semiconductors. , 1990, Physical review. B, Condensed matter.

[33]  Min Xie,et al.  Stress and its effect on optical properties of GaN epilayers grown on Si(111), 6H-SiC(0001), and c-plane sapphire , 2003 .

[34]  E. Fred Schubert,et al.  Effect of dislocation density on efficiency droop in GaInN∕GaN light-emitting diodes , 2007 .

[35]  C. Kuo,et al.  ACTIVATION ENERGIES OF SI DONORS IN GAN , 1996 .

[36]  M. Basavaraj,et al.  The influence of phonons on the optical properties of GaN , 2006 .