Resonant Raman and FTIR spectra of carbon doped GaN

Ito, Shotaro; Kobayashi, Hidetoshi; Araki, Koji; Suzuki, Kazuyuki; Sawaki, Nobuhiko; Yamashita, K.; Honda, Yoshio; Amano, Hiroshi

doi:10.1016/j.jcrysgro.2014.11.024

Cited by 19 publications

(7 citation statements)

References 48 publications

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“…The broad high signal in the range from about 450 to 800 cm −1 is assigned to one‐phonon absorption. On its high‐energy flank, a narrow peak at 777.5 cm −1 can be seen which was already assigned as the local vibrational mode (LVM) of the substitutional carbon acceptor C N on nitrogen site . A next broad band from 1100 to 1400 cm −1 can be assigned to combination absorption.…”

Section: Resultsmentioning

confidence: 94%

“…On its high-energy flank, a narrow peak at 777.5 cm −1 can be seen which was already assigned as the local vibrational mode (LVM) of the substitutional carbon acceptor C N on nitrogen site. [30] A next broad band from 1100 to 1400 cm −1 can be assigned to combination absorption. But then, at 1679 cm −1 and at 1718 cm −1 , two additional peaks occur which are similar to the LVM of the tri-carbon defect found in AlN.…”

Section: Resultsmentioning

confidence: 99%

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Growth and Properties of Intentionally Carbon‐Doped GaN Layers

Richter

Beyer

Zimmermann

et al. 2019

Crystal Research and Technology

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Carbon-doping of GaN layers with thickness in the mm-range is performed by hydride vapor phase epitaxy. Characterization by optical and electrical measurements reveals semi-insulating behavior with a maximum of specific resistivity of 2 × 10 10 cm at room temperature found for a carbon concentration of 8.8 × 10 18 cm −3 . For higher carbon levels up to 3.5 × 10 19 cm −3 , a slight increase of the conductivity is observed and related to self-compensation and passivation of the acceptor. The acceptor can be identified as C N with an electrical activation energy of 0.94 eV and partial passivation by interstitial hydrogen. In addition, two differently oriented tri-carbon defects, C N -a-C Ga -a-C N and C N -a-C Ga -c-C N , are identified which probably compensate about two-thirds of the carbon which is incorporated in excess of 2 × 10 18 cm −3 .

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Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 99%

Growth and Properties of Intentionally Carbon‐Doped GaN Layers

Richter

Beyer

Zimmermann

et al. 2019

Crystal Research and Technology

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“…Vibrational modes of undoped GaN and doped GaN have been investigated by Raman spectra (Figure 3a), and the different modes were assigned on the basis of theoretical and experimental reports by Wu et al and Ito et al 8,11 Besides E 2 (high) and A 1 (LO) modes, a new vibrational mode is observed in heavily C doped GaN:C N at ∼765 cm −1 (ω 1 ). This can be further resolved in four modes located at 765(C N − ,ν 1 ), 777 cm −1 (C N − ,ν 2 ), 781 cm −1 (C N − ,ν 3 ), and ∼803 cm −1 (C N − O N 0 , ν) (Figure 3a).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Although, over the years, multiple theoretical and experimental approaches have been used for understanding the nature of these defect states, their respective energy levels, and the related emissions; an experimental characterization of YL is still needed. A study on substrate-free C-doped GaN is of interest for vibrational spectroscopic characterizations as a Reststrahlen-related band exhibition of the substrate obstructs localized vibrational modes (LVMs) of a carbon dopant in GaN. − …”

Section: Introductionmentioning

confidence: 99%

An Experimental Study of Carbon-Doped GaN via Solid–Gas Reaction Route and Investigation of Its Defect-Related Luminescence

Singh

Roy

Rao

2022

ACS Appl. Electron. Mater.

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Carbon-doped gallium nitride (GaN) is a very interesting material with applications in optoelectronic devices, and studies related to their defects offer insights regarding possible transitions based on the nature of the defects. A simple solid−gas reaction route has yielded carbon-doped GaN. An isolated C N defect state has been observed by spectroscopic tools (Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy) along with the C N −O N complex formation. In addition to the red shift in the fundamental absorption band, a transition band was observed at ∼3.05 eV. A complete quenching of blue luminescence (BL) related to an oxygen defect and the appearance of a carbon-related yellow luminescence (YL) is shown in strongly doped samples. The origin of this defect-related YL in Cdoped GaN is attributed to the carbon-defect C N (−1 charged) level transitions confirmed by absorption energy, photoluminescence (PL) peak position, and zero-phonon line.

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“…23) or a kind of complex, such as the Al-C-O complex. 24,25 To further verify the existence of graphitic C on the sapphire surface after the preflow process, Raman measurements were carried out on the TMAl-only samples. Raman measurements were carried out on the TMAl-only samples in a Horiba Jobin Yvon confocal Micro-Raman HR 800 system, using a 473 nm laser excitation source.…”

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confidence: 99%

Influence of TMAl preflow on AlN epitaxy on sapphire

Sun

Park

et al. 2017

Applied Physics Letters

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The trimethylaluminum (TMAl) preflow process has been widely applied on sapphire substrates prior to growing Al-polar AlN films by metalorganic chemical vapor deposition. However, it has been unclear how the TMAl preflow process really works. In this letter, we reported on carbon's significance in the polarity and growth mode of AlN films due to the TMAl preflow. Without the preflow, no trace of carbon was found at the AlN/sapphire interface and the films possessed mixed Al- and N-polarity. With the 5 s preflow, carbon started to precipitate due to the decomposition of TMAl, forming scattered carbon-rich clusters which were graphitic carbon. It was discovered that the carbon attracted surrounding oxygen impurity atoms and consequently suppressed the formation of AlxOyNz and thus N-polarity. With the 40 s preflow, the significant presence of carbon clusters at the AlN/sapphire interface was observed. While still attracting oxygen and preventing the N-polarity, the carbon clusters served as randomly distributed masks to further induce a 3D growth mode for the AlN growth. The corresponding epitaxial growth mode change is discussed.

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Resonant Raman and FTIR spectra of carbon doped GaN

Cited by 19 publications

References 48 publications

Growth and Properties of Intentionally Carbon‐Doped GaN Layers

Growth and Properties of Intentionally Carbon‐Doped GaN Layers

An Experimental Study of Carbon-Doped GaN via Solid–Gas Reaction Route and Investigation of Its Defect-Related Luminescence

Influence of TMAl preflow on AlN epitaxy on sapphire

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