<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>p</mml:mi></mml:math>- and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>n</mml:mi></mml:math>-type cubic GaN epilayers on GaAs

As, D. J.; Schikora, D.; Greiner, Andreas; Lübbers, M.; Mimkes, Jürgen; Lischka, K.

doi:10.1103/physrevb.54.r11118

Cited by 58 publications

(38 citation statements)

References 15 publications

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“…The absence of built-in fields is expected to yield a superior stability of the emission wavelength with increasing current and to increase the radiative efficiency in the well. The zinc-blende polytype of GaN, with a band gap 0.2 eV lower than that of the wurtzite phase [3] and higher hole mobility [4], is being considered as an alternative to the growth along nonpolar axes of wurtzite to address the droop problem in green light-emitting diodes [2]. The lower band gap of the cubic form requires less In alloying to reach the green emission region and, because of the absence of polarization fields, wider wells can be used where the carrier density is lower and hence the Auger nonradiative recombination rate [5] is reduced.…”

Section: Introductionmentioning

confidence: 99%

Anharmonic phonon decay in cubic GaN

et al. 2015

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We present a Raman-scattering study of optical phonons in zinc-blende (cubic) GaN for temperatures ranging from 80 to 750 K. The experiments were performed on high-quality, cubic GaN films grown by molecular-beam epitaxy on GaAs (001) substrates. The observed temperature dependence of the optical phonon frequencies and linewidths is analyzed in the framework of anharmonic decay theory, and possible decay channels are discussed in the light of density-functional-theory calculations. The longitudinal-optical (LO) mode relaxation is found to occur via asymmetric decay into acoustic phonons, with an appreciable contribution of higher-order processes. The transverse-optical mode linewidth shows a weak temperature dependence and its frequency downshift is primarily determined by the lattice thermal expansion. The LO phonon lifetime is derived from the observed Raman linewidth and an excellent agreement with previous theoretical predictions is found.

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Section: Introductionmentioning

confidence: 99%

Anharmonic phonon decay in cubic GaN

et al. 2015

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“…The MOVPE samples, predominantly also n-conducting, were grown with GaN or AlN buffer layers in order to decrease the background carrier concentration [10,11]; they are only a few µm thick. The cubic GaN samples were exclusively grown with MBE on (001) GaAs substrates [12,13]. Their thickness runs from a few nm to 1.8 µm and their free carrier concentrations (n-type) from 10 18 to 10 20 cm -3 .…”

Section: Experimental 21 Samplesmentioning

confidence: 99%

Lattice dynamics in GaN and AlN probed with first‐ and second‐order Raman spectroscopy

Haboeck

Siegle

Hoffmann

et al. 2003

phys. stat. sol. (c)

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We present a selection of our contributions to basic research on the lattice dynamical properties of group-III nitrides and their alloys. We used first-order Raman scattering to determine the zone-center phonons and their dependence on structural attributes such as stress, chemical composition, impurities, and doping. Results on the angular dispersion of the polar modes, strain distribution, coupled LO-phonon plasmon modes, multi-mode behavior in Al x Ga 1-x N, and the quantitative determination of the phase purity of cubic and hexagonal GaN are shown. Second-order Raman-scattering experiments on GaN and AlN provide information on the vibrational states throughout the entire Brillouin zone. Based on a comparison of experimental data and calculated phonon-dispersion curves we assigned the observed structures to particular phonon branches and points in the Brillouin zone. We also discuss the behavior of the optical modes under large hydrostatic pressure. 1 Introduction During the last decade group-III nitrides have been an object of increasing research because of their interesting physical properties such as an adjustable band gap (1.9 eV to 6.2 eV) by varying the composition of the alloys [1] and application as basic materials for optoelectronic devices working in the blue and ultraviolet spectral region [2][3][4]. In particular GaN and AlN can withstand high temperatures and have large piezoelectric constants which makes them suitable for applications in highfrequency devices, sensors and low-dimensional structures [5,6].Although basic information about group-III nitrides e.g. crystal-and band structure have been available for a decade several details still remained unclear. In the following review of our work we present results of first-and second-order Raman investigations on various GaN, AlN, and Al x Ga 1-x N samples and point out some remarkable details of the structural and optical properties of these materials.

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“…The epitaxy of metastable, cubic GaN on GaAs (001) substrates has attracted some interest recently since c-GaN layers and the GaAs substrate have a common cleavage plane, they are considered to be well suited for the fabrication of laser cavities with cleaved facets [1][2][3][4][5][6][7][8]. [2].…”

Section: Introductionmentioning

confidence: 99%

Mechanisms of Optical Gain in Cubic GaN and InGaN

Holst

Hoffmann

Broser

et al. 1999

MRS Internet j. nitride semicond. res.

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The epitaxial growth of zinc-blende (cubic) GaN and InGaN on GaAs with a common cleavage plane and readily high-quality, low-cost wafers may be considered as an alternative approach for the future realization of cleaved laser cavities. To obtain detailed information about the potential of cubic GaN and InGaN for device applications we performed optical gain spectroscopy accompanied by time-integrated and time-dependent photoluminescence measurements at 2 K and 300 K. From intensity-dependent gain measurements, the identification of the gain processes was possible. For moderate excitation levels, the biexciton decay is likely to be responsible for a gain structure at 3.265 eV in cubic GaN [10]. For the highest pump intensities, the electron-hole-plasma is the dominant gain process, providing gain values up to 200 cm -1 . Furthermore cubic GaN samples with different cavity lengths from 250 to 600 µm were cleaved to investigate the influence of the sample geometry on the gain mechanisms. In these samples increased gain values up to 150 cm -1 as well as lower threshold excitation densities were observed, indicating the potential of cubic GaN for device applications. The results of GaN will be compared with intensity-dependent gain measurements on InGaN samples, grown on GaAs with varying In-content. The observed gain mechanisms in cubic InGaN will be discussed in detail.

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p- andn-type cubic GaN epilayers on GaAs

Cited by 58 publications

References 15 publications

Anharmonic phonon decay in cubic GaN

Anharmonic phonon decay in cubic GaN

Lattice dynamics in GaN and AlN probed with first‐ and second‐order Raman spectroscopy

Mechanisms of Optical Gain in Cubic GaN and InGaN

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