Optical phonons of hexagonal AlxGa1−xN: Simulation and experiment

The behavior of longitudinal and transverse optical phonons in hexagonal AlxGa1−xN is derived theoretically and experimentally as a function of the concentration x(0⩽x⩽1). The theoretical approach is based on a modified random element isodisplacement model which considers the interactions with the nearest neighbor and second neighbor atoms. We find “one-mode” behavior in AlxGa1−xN in which the phonon frequency in general varies continuously and approximately linearly with x. The theoretical simulations are in good agreement with Raman scattering experiments, which also reveal that both the linewidth and intensity of the optical phonons strongly depend on the concentration.

[1]  Klaus Lischka,et al.  Comparative Raman studies of cubic and hexagonal GaN epitaxial layers , 1996 .

[2]  T. Metzger,et al.  Raman study of the optical phonons in AlxGa1−xN alloys , 1997 .

[3]  Shuji Nakamura,et al.  The Blue Laser Diode: GaN based Light Emitters and Lasers , 1997 .

[4]  J. Woicik,et al.  EXTENDED X-RAY ABSORPTION FINE STRUCTURE STUDY OF ALXGA(1-X)N FILMS , 1997 .

[5]  K. Bachem,et al.  Resonant Raman scattering in GaN/(AlGa)N single quantum wells , 1997 .

[6]  Friedhelm Bechstedt,et al.  Phonons in ternary group-III nitride alloys , 2000 .

[7]  A. S. Barker,et al.  Optical Phonons in Mixed Crystals of CdSe y S 1-y , 1967 .

[8]  P. Vogl,et al.  Dependence on volume of the phonon frequencies and the ir effective charges of several III-V semiconductors , 1983 .

[9]  Ramdas,et al.  Raman scattering from the vibrational modes in Zn1-xMnxTe. , 1986, Physical review. B, Condensed matter.

[10]  M. Born,et al.  Dynamical Theory of Crystal Lattices , 1954 .

[11]  Richard M. Martin,et al.  Light scattering study of boron nitride microcrystals , 1981 .

[12]  T. Kistenmacher,et al.  THE EFFECT OF THERMAL ANNEALING ON GAN NUCLEATION LAYERS DEPOSITED ON (0001) SAPPHIRE BY METALORGANIC CHEMICAL VAPOR DEPOSITION , 1994 .

[13]  S. Prawer,et al.  Dependence on Al concentration of the optical phonons of AlxGa1−xN films , 1998 .

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

[15]  J. Groenen,et al.  Raman study of Ga 1−x Al x N solid solutions , 1997 .

[16]  H. Morkoç,et al.  GaN, AlN, and InN: A review , 1992 .

[17]  F. Bechstedt,et al.  Raman studies on phonon modes in cubic AlGaN alloy , 1999 .

[18]  Shen,et al.  Optical-phonon behavior in Zn1-xMnxSe: Zinc-blende and wurtzite structures. , 1993, Physical review. B, Condensed matter.

[19]  O. Zelaya-Ángel,et al.  Optical phonons in ZnxCd1−xSe thin films , 1996 .

[20]  S. Prawer,et al.  Optical Phonons in Cubic AlxGa1-xM Approached by the Modified Random Element Isodisplacement Model , 1998 .

[21]  S. Misawa,et al.  Properties of AlxGa1−xN films prepared by reactive molecular beam epitaxy , 1982 .

[22]  I. Akasaki,et al.  Raman scattering in AlxGa1−xN alloys , 1991 .

[23]  M. Paisley,et al.  Structural Defects in GaN Epilayers Grown by Gas Source Molecular Beam Epitaxy , 1989 .

[24]  J. F. Schetzina,et al.  UV-Specific (320-365 nm) Digital Camera Based On a 128×128 Focal Plane Array of GaN/AlGaN p-i-n Photodiodes , 2000 .

[25]  L. Genzel,et al.  Model for Long ‐ Wavelength Optical‐Phonon Modes of Mixed Crystals , 1974 .

[26]  S. Prawer,et al.  Micro-Raman scattering properties of highly oriented AlN films , 1998 .

[27]  Guanghong Wei,et al.  Lattice dynamics of zinc-blende GaN and AlN: I. Bulk phonons , 1996 .

[28]  R. French,et al.  Vibrational Spectroscopy of Aluminum Nitride , 1993 .

[29]  Shuji Nakamura,et al.  Polarized Raman spectra in GaN , 1995 .

[30]  Suski,et al.  Raman-scattering studies of aluminum nitride at high pressure. , 1993, Physical review. B, Condensed matter.

[31]  F. Bechstedt,et al.  Anion‐Related Differences in Phonons of (GaX)N(Ga1‐xAlxX)N(001) Superlattices (X=As,N) , 1996 .

[32]  M. Dutta,et al.  Raman analysis of the configurational disorder in AlxGa1−xN films , 1997 .

[33]  I. F. Chang,et al.  Application of a Modified Random-Element-Isodisplacement Model to Long-Wavelength Optic Phonons of Mixed Crystals , 1968 .