Progress in AlInN-GaN Bragg reflectors: Application to a microcavity light emitting diode

We report on the progress in the growth of highly reflective AlInN-GaN distributed Bragg reflectors deposited by metalorganic vapor phase epitaxy. Al1-xInxN layers with an In content around x similar to 0.17 are lattice-matched to GaN, thus avoiding strain-related issues in the mirror while keeping a high refractive index contrast of about 7%. Consequently, a reflectivity value as high as 99.4% at 450 nm was achieved with a 40-pair crack-free distributed Bragg reflector. We measured an average absorption coefficient alpha [cm(-1)] in the AlInN-GaN Bragg reflectors of 43 +/- 14 cm(-1) at 450 nm and 75 +/- 19 cm(-1) at 400 nm. Application to blue optoelectronics is demonstrated through the growth of an InGaN-GaN microcavity light emitting diode including a 12-pair Al0.82In0.18N-GaN distributed Bragg reflector as bottom mirror. The device exhibits clear microcavity effects, improved directionality in the radiation pattern and an optical output power of 1.7 mW together with a 2.6% external quantum efficiency at 20 mA. (C) 2005 American Institute of Physics.

[1]  Theodore D. Moustakas,et al.  High reflectivity and broad bandwidth AlN/GaN distributed Bragg reflectors grown by molecular-beam epitaxy , 2000 .

[2]  Ratna Naik,et al.  Optical and electrical properties of Al1−xInxN films grown by plasma source molecular-beam epitaxy , 2001 .

[3]  A. Nurmikko,et al.  Stress Engineering During Metalorganic Chemical Vapor Deposition of AlGaN/GaN Distributed Bragg Reflectors , 2001 .

[4]  Takashi Mukai,et al.  High-Power GaN P-N Junction Blue-Light-Emitting Diodes , 1991 .

[5]  Pleun Maaskant,et al.  Experimental characterisation of GaN-based resonant cavity light emitting diodes , 2002 .

[6]  Oliver Ambacher,et al.  Optical constants of epitaxial AlGaN films and their temperature dependence , 1997 .

[7]  Joachim Piprek,et al.  Band gap bowing and refractive index spectra of polycrystalline AlxIn1−xN films deposited by sputtering , 1997 .

[8]  O. Brandt,et al.  Crack-free and conductive Si-doped AlN∕GaN distributed Bragg reflectors grown on 6H-SiC(0001) , 2004 .

[9]  H. Benisty,et al.  Method of source terms for dipole emission modification in modes of arbitrary planar structures , 1998 .

[10]  Satoshi Kamiyama,et al.  Recombination dynamics of localized excitons in Al1−xInxN epitaxial films on GaN templates grown by metalorganic vapor phase epitaxy , 2003 .

[11]  Takashi Matsuoka,et al.  Calculation of unstable mixing region in wurtzite In1−x−yGaxAlyN , 1997 .

[12]  H. Amano,et al.  Structural Properties of Al 1- xIn xN Ternary Alloys on GaN Grown by Metalorganic Vapor Phase Epitaxy , 1998 .

[13]  Pleun Maaskant,et al.  Fabrication of GaN‐Based Resonant Cavity LEDs , 2002 .

[14]  J. Carlin,et al.  High-quality AlInN for high index contrast Bragg mirrors lattice matched to GaN , 2003 .

[15]  Oliver Ambacher,et al.  Sub-bandgap absorption of gallium nitride determined by Photothermal Deflection Spectroscopy , 1996 .

[16]  Bernard Beaumont,et al.  METALORGANIC VAPOR-PHASE EPITAXY-GROWN ALGAN MATERIALS FOR VISIBLE-BLIND ULTRAVIOLET PHOTODETECTOR APPLICATIONS , 1999 .

[17]  Manijeh Razeghi,et al.  Determination of the band-gap energy of Al 12x In x N grown by metal-organic chemical-vapor deposition , 1997 .

[18]  S. Nakamura,et al.  InGaN-Based Multi-Quantum-Well-Structure Laser Diodes , 1996 .

[19]  C. Weisbuch,et al.  Impact of planar microcavity effects on light extraction-Part I: basic concepts and analytical trends , 1998 .

[20]  H. Ogawa,et al.  Crystal Structure and Orientation of AlxIn$_{{\bf 1}-\ninmb{x}}$N Epitaxial Layers Grown on (0001) \mbα-Al$_{\bf 2}$O$_{\bf 3}$ Substrates , 1995 .