Effect of Si doping on structural, photoluminescence and electrical properties of GaN

Shmidt, N. M.; Lebedev, A. A.; Lundin, W. V.; Pushnyi, B. V.; Ратников, В. В.; Shubina, T. V.; Tsatsul'nikov, Andrei; Usikov, A.; Pozina, Galia; Ḿonemar, B.

doi:10.1016/s0921-5107(98)00400-0

Cited by 10 publications

(7 citation statements)

References 4 publications

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“…Additionally, the exciton positions E DBE are shifted to higher energies with respect to the energetic position of strain-free homoepitaxial grown GaN (3.471 eV [11]). The shift, ∆E DBE (Table I), is slightly larger for the MOCVD-GaN undoped sample compared to the Si-doped one, due to a higher compressive stress in the layer and consistent with previously reported results [6,7]. The shift is much smaller in HVPE-GaN layers grown on MOCVD buffers, indicative of a presence of a relaxation mechanism in the structure.…”

Section: Resultssupporting

confidence: 90%

“…That is why we investigate both type of MOCVD 'templates', slightly doped to a concentration of 1.8x10 18 cm -3 and undoped layers as buffers for a consequent HVPE growth of thick layers. The material parameters of both MOCVD 'templates' are summarised in Table I, and a good agreement with previous results reported for similar samples can be seen [6,7]. Fig.1(a) shows a cross-section of the layer grown by conventional nitridation pretreatment of sapphire and Fig.1(b) and (c) show the cross-sections of the layers grown on MOCVD 'templates' intentionally doped with Si and undoped, respectively.…”

Section: Resultssupporting

confidence: 83%

“…Simultaneously, the density of misfit dislocations parallel to the interface has increased [7]. Such structural peculiarities have been found to promote an increase in mobility in the Si-doped epilayers [7]. That is why we investigate both type of MOCVD 'templates', slightly doped to a concentration of 1.8x10 18 cm -3 and undoped layers as buffers for a consequent HVPE growth of thick layers.…”

Section: Resultsmentioning

confidence: 99%

“…Doping of the MOCVD-GaN by Si to a concentration of (3-8)x10 18 cm -3 has been reported to reduce the biaxial stress in the layers as well as to reduce the density of vertical screw and edge dislocations along the c-axis [6,7]. Simultaneously, the density of misfit dislocations parallel to the interface has increased [7]. Such structural peculiarities have been found to promote an increase in mobility in the Si-doped epilayers [7].…”

Section: Resultsmentioning

confidence: 99%

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Hydride Vapour Phase Homoepitaxial Growth of GaN on MOCVD-Grown ‘Templates’

Paskova

Tungasmita

Valcheva

et al. 2000

MRS Internet j. nitride semicond. res.

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We report on an improved quality of thick HVPE-GaN grown on MOCVD-GaN ‘template’ layers compared to the material grown directly on sapphire. The film-substrate interface revealed by cathodoluminescence measurements shows an absence of highly doped columnar structures which are typically present in thick HVPE-GaN films grown directly on sapphire. This improved structure results in a reduction of two orders of magnitude of the free carrier concentration from Hall measurements. It was found that the structure, morphology, electrical and optical properties of homoepitaxial thick GaN layers grown by HVPE were strongly influenced by the properties of the MOCVD-GaN ‘template’. Additionally the effect of Si doping of the GaN buffer layers on the HVPEGaN properties was analysed.

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Section: Resultssupporting

confidence: 90%

Section: Resultssupporting

confidence: 83%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Hydride Vapour Phase Homoepitaxial Growth of GaN on MOCVD-Grown ‘Templates’

Paskova

Tungasmita

Valcheva

et al. 2000

MRS Internet j. nitride semicond. res.

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“…It indicates that the moderate Si doping improves the optical properties of GaN epitaxial films. This fact is in agreement with the data of paper [3], where it was shown that Si doping results in decreasing of dislocation density and in compensating of native defects of GaN epilayers which improve some of their electrophysical properties. At further growth of doping concentration the width of the bound exciton emission line increases and the line intensity rises whereas the position shifts to the low-energy side, so at the doping concentration of 2 Â 10 19 cm ± ±3 the line is situated at 3.47 eV.…”

supporting

confidence: 93%

Photoluminescence and Absorption Edge of Undoped and Doped GaN Films

Jacobson¹,

Nelson²,

Romanovsky³

1998

phys. stat. sol. (b)

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Photoluminescence and absorption spectra of undoped and Si-doped GaN films have been studied. It was shown that moderate Si doping improves the optical properties of GaN epitaxial layers. The further increase of doping concentration results in a red shift and broadening of bound exciton line. The broadening seems to be due to potential fluctuations caused by randomly distributed donor impurities. The analysis of temperature dependence of GaN photoluminescence spectra allowed us to reveal the E 1 2 optical-phonon replica of free exciton. The observed flattening of absorption edge with doping can be described in terms of Urbach rule.

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Electrical and optical properties of silicon-doped gallium nitride polycrystalline films

Bhattacharyya

Pal

2008

Bull Mater Sci

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Si-doped GaN films in polycrystalline form were deposited on quartz substrates at deposition temperatures ranging from 300-623 K using r.f. sputtering technique. Electrical, optical and microstructural properties were studied for these films. It was observed that films deposited at room temperature contained mainly hexagonal gallium nitride (h-GaN) while films deposited at 623 K were predominantly cubic (c-GaN) in nature. The films deposited at intermediate temperatures were found to contain both the hexagonal and cubic phases of GaN. Studies on the variation of conductivity with temperature indicated Mott's hopping for films containing c-GaN while Efros and Shklovskii (E-S) hopping within the Coulomb gap was found to dominate the carrier transport mechanism in the films containing h-GaN. A crossover from Mott's hopping to E-S hopping in the 'soft' Coulomb gap was noticed with lowering of temperature for films containing mixed phases of GaN. The relative intensity of the PL peak at ~2⋅73 eV to that for peak at ~3⋅11 eV appearing due to transitions from deep donor to valence band or shallow acceptors decreased significantly at higher temperature. Variation of band gap showed a bowing behaviour with the amount of cubic phase present in the films.

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Effect of Si doping on structural, photoluminescence and electrical properties of GaN

Cited by 10 publications

References 4 publications

Hydride Vapour Phase Homoepitaxial Growth of GaN on MOCVD-Grown ‘Templates’

Hydride Vapour Phase Homoepitaxial Growth of GaN on MOCVD-Grown ‘Templates’

Photoluminescence and Absorption Edge of Undoped and Doped GaN Films

Electrical and optical properties of silicon-doped gallium nitride polycrystalline films

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