Growth and Surface Reconstructions of AlN(0001) Films

Lee, C. D.; Yang, Dong; Feenstra, R. M.; Northrup, John E.; Neugebauer, Jörg

doi:10.1557/proc-798-y3.5

Cited by 3 publications

(3 citation statements)

References 13 publications

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“…Therefore, a smooth AlN (0001) surface is polar. Both experimental and theoretical studies showed reconstruction of the Al (0001) surfaces . Our goal here is for understanding the Eu preference in the bulk or at the surfaces of AlN.…”

Section: Resultsmentioning

confidence: 99%

Direct observation of Eu atoms in AlN lattice and the first‐principles simulations

et al. 2018

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Rare-earth metal (Eu)-doped aluminum nitride has potential application as luminescence materials due to its unusual mechanical and physical properties, as well as high chemical stability. Here, we investigate the energetics, local structure and optical and electronic properties by means of a combination of experimental observations (XDR, SEM, HR-TEM and XANES) and first-principles simulations. Present study has revealed that Eu ions are likely to be co-doped with O in the form of Eu-O pairs. Eu ions or Eu-O pairs favor participation at the surfaces of the AlN crystallites. Our analyses show dependences of the Eu valence and electronic/optical properties on the local chemical composition and structure. The obtained information helps us to realize tuning of the optical properties of the luminescent materials via composition and site occupation modification. K E Y W O R D S AlN, Eu site, first-principle calculation, phosphor Liang-Jun Yin and Sheng-Hui Zhang contributed equally to this manuscript.

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Section: Resultsmentioning

confidence: 99%

Direct observation of Eu atoms in AlN lattice and the first‐principles simulations

et al. 2018

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“…[7][8][9][10][11] To date, traditional research on AlGaN-MOCVD growth has been based either on a two-dimensional model [12][13][14] or the model of a small reactor. [15][16][17][18][19][20] Due to the great potential for development of AlGaN film , large-capacity reactors and that uniformity of growth rate and substrate thickness are required. In the MOCVD process, the gas flow, heat distribution, and concentration distribution in the reactor are vital to ensure an appropriate growth efficiency and thickness uniformity of the thin film.…”

Section: Introductionmentioning

confidence: 99%

Process parameters simulation and analysis of a new reactor for high temperature MOCVD AlGaN growth

An,

Dai,

Liu

et al. 2023

Preprint

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Commercially, metal organic chemical vapor deposition (MOCVD) is a typical and effective approach to the AlGaN film growth. It is believed that high temperature growth condition is favorable for improving efficiency and crystallization quality for the film. However, problems such as low growth rate and poor crystallization quality are common in the growing process. Considering the process conditions, such as operating pressure, gas flow rate and rotation speed, and to ensure the uniformity of growth rate and substrate thickness, a new high-temperature reactor is proposed in this paper. The process parameters were optimized by CFD simulation and the finite element analysis was conducted on the temperature field, pressure field, velocity field, density field and other physical fields. These conditions make the flow field in the reactor stable and ensure the thickness uniformity of the deposited films. These research not only provide an effective solution for high quality MOCVD AlGaN growth, but also provide a theoretical basis for experiments and equipment improvement that follows.

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“…(a) RHEED pattern shows 1st order streaks from excess Al overlayer when viewed along[11][12][13][14][15][16][17][18][19][20] for Al-rich growth (b) RHEED pattern shows bright sharp streaks when excess Al gets consumed.The active region of the two LEDs consists of 8-periods of the GaN quantum dot/AlN barrier heterostructure as shown inFigure 2(a). The active region quantum dots were grown in the Stranski-Krastonov mode with 25 s growth time The ninjection layer for all three LEDs is a ∼225 nm Si-doped high composition AlGaN with doping density N D ∼ 5×10 19 /cm 3 .…”

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confidence: 99%

Boost in deep-UV electroluminescence from tunnel-injection GaN/AlN quantum dot LEDs by polarization-induced doping

et al. 2014

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GaN/AlN quantum dots (QDs) have been observed to emit in deep ultra violet (UV) regime. The emission wavelength can be tuned from 270 nm to 238 nm using GaN growth time and Ga flux. In this work, tunnel injection GaN/AlN QD UV LEDs have been fabricated utilizing polarization doped p-n junctions grown on AlN templates on sapphire. The QD EL emission is obtained at 250 nm whereas a second peak emission is observed at 290 nm from the p-type AlGaN. However, the enhanced doping and carrier injection in polarization doped structure boosts the deep-UV emission intensity by 26 times compared to non-polarization doped UV LED.

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Growth and Surface Reconstructions of AlN(0001) Films

Cited by 3 publications

References 13 publications

Direct observation of Eu atoms in AlN lattice and the first‐principles simulations

Direct observation of Eu atoms in AlN lattice and the first‐principles simulations

Process parameters simulation and analysis of a new reactor for high temperature MOCVD AlGaN growth

Boost in deep-UV electroluminescence from tunnel-injection GaN/AlN quantum dot LEDs by polarization-induced doping

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