Low-temperature synthesis and photoluminescence of AlN

Lan, Yucheng; Chen, X.L; Cao, Yongge; Xu, Yu; Xun, Liang; Xu, Tao; Liang, J. K.

doi:10.1016/s0022-0248(99)00448-0

Cited by 75 publications

(51 citation statements)

References 17 publications

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“…The origin of the defect centers is assumed to be related to oxygen complexes and related defects as previously reported. 20,21 The PL peak around $4.1 eV is detected in all samples and cannot be directly correlated to oxygen and hence, other impurities such as nitrogen vacancies, Al-N antisites, and related complexes might be the origin of these interior band gap transitions. Further investigation is needed to clarify this issue.…”

mentioning

confidence: 97%

Optical properties of AlN thin films grown by plasma enhanced atomic layer deposition

Alevli

Ozgit

Dönmez

et al. 2012

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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Crystalline aluminum nitride (AlN) films have been prepared by plasma enhanced atomic layer deposition within the temperature range of 100 and 500 °C. The AlN films were characterized by x-ray diffraction, spectroscopic ellipsometry, Fourier transform infrared spectroscopy, optical absorption, and photoluminescence. The authors establish a relationship between growth temperature and optical properties and in addition, the refractive indices of the AlN films were determined to be larger than 1.9 within the 300-1000 nm wavelength range. Infrared reflectance spectra confirmed the presence of E 1(TO) and A 1(LO) phonon modes at ∼660 cm -1 and 895 cm -1, respectively. Analysis of the absorption spectroscopy show an optical band edge between 5.78 and 5.84 eV and the absorption and photoluminescence emission properties of the AlN layers revealed defect centers in the range of 250 and 300 nm at room temperature. © 2012 American Vacuum Society

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mentioning

confidence: 97%

Optical properties of AlN thin films grown by plasma enhanced atomic layer deposition

Alevli

Ozgit

Dönmez

et al. 2012

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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“…Specifically, the intensive light emission from AlN materials has generally been attributed to the nitrogen deficiency and the radiative recombination of a photon-(or electron-) generated hole with an electron occupying the nitrogen deficiency; [5] this phenomenon has also been observed previously in AlN thin-film and nanodot structures. [22,23] The intensive CL emission indicates that wellaligned, columnar AlN nanorods with multiple-nanotip surfaces have potential application in light-emitting nanodevices. In summary, this study presents a method for growing wellaligned, columnar AlN nanorods with multiple-nanotip surfaces via the reaction of AlCl 3 and (NH 4 ) 2 CO 3 by a VS process.…”

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confidence: 99%

Aligned AlN Nanorods with Multi‐tipped Surfaces—Growth, Field‐Emission, and Cathodoluminescence Properties

et al. 2006

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Aluminum nitride, an important member of the group III nitrides with the highest bandgap of about 6.2 eV, has excellent thermal conductivity, good electrical resistance, low dielectric loss, high piezoelectric response, and ideal thermal expansion, matching that of silicon.[1] The interest in field-emission (FE) applications of AlN materials has grown because they exhibit a negative electron affinity.[2] Exhibiting a negative electron affinity means that electrons excited into the conduction band can be freely emitted into vacuum. In addition, high-current emission at a relatively low field is most attractive for FE applications. As a result, significant effort is being devoted to reducing the tip size and increasing the density of the emitting sites by using hierarchical nanostructures. Therefore, the synthesis of AlN nanostructures, such as nanowires, [3] nanotubes, [4] nanocones, [5] nanotips, [6,7] hierarchical comb-like structures, [8] and nanobelts, [9] with controlled high-aspect-ratio shapes and sizes is an important topic worthy of exploration. The promise that one-dimensional (1D) ), [5] nanotips (3.1-4.7 V lm -1 ), [6,7] and hierarchical comb-like structures (2.45-3.76 V lm -1).[8] On the other hand, reports on the luminescence properties of AlN nanostructures are scarce.[9] The AlN nanocones have been observed to have an emission band centered at 481 nm, referred to as a deeplevel or trap-level state.[5]In the present study, we report the growth of well-aligned AlN nanorods with hairy surfaces by a vapor-solid (VS) process. The well-aligned AlN nanorods with hairy surfaces reported here not only provide a new hierarchical nanostructure, but also serve as a promising candidate for FE emitters because of their low electron affinity and the geometry of the multiple-nanotip surfaces. Compared with previous reports on hierarchal growth of AlN nanostructures, [8,10] in this communication we report a higher density of smaller nanotips (∼ 3-15 nm) that were radially grown on the surfaces of AlN nanorods. Each nanotip may serve as an ultrasmall emitter. In addition, growing well-aligned AlN nanorods on Si substrates is amenable to current technology for the fabrication of Sibased microelectronics devices. The subsequent characterization of their cathodoluminescence (CL) reveals that these hierarchical AlN nanostructures possess an intense emission peak, further suggesting potential applications in optoelectronic nanodevices. The structure of the as-grown products has been determined by X-ray diffraction (XRD). As shown in Figure 1, all of the diffraction peaks in the XRD pattern can be identified; they correspond to a hexagonal wurtzite-structured AlN crystal with lattice constants of a = 0.3114 nm and c = 0.4986 nm, consistent with the Joint Committee Powder Diffraction Standard (JCPDS) data file . No other impurity phases were found in the XRD pattern.The morphology of the as-synthesized products has been characterized by scanning electron microscopy (SEM). As shown in Figure 2a, a typical low-magnification...

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“…Then the ammonothermally treated powders are collected, filtered, thoroughly washed with distilled water and ethanol in sequence, and dried at room temperature in vacuum. The details of the ammonothermal procedure have been described in other literatures [17][18][19].…”

Section: Methodsmentioning

confidence: 99%

Chemical Reduction of Nd_1.85Ce_0.15CuO_4−δPowders in Supercritical Sodium Ammonia Solutions

Dias

Wang

Zhou

et al. 2015

Advances in Condensed Matter Physics

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Nd 1.85 Ce 0.15 CuO 4− powders are chemically reduced in supercritical sodium ammonia solutions from room temperature to 350 ∘ C. The crystallographic structure of the reduced powders is investigated from Rietveld refinement of X-ray powder diffraction. The atomic positions are maintained constant within experimental errors while temperature factors of all atoms increase significantly after the chemical treatments, especially of Nd/Ce atoms. The ammonothermally reduced Nd 1.85 Ce 0.15 CuO 4− powders show diamagnetic below 24 K which is contributed to the lower oxygen content and higher temperature factors of atoms in the treated compound. The ammonothermal method paves a new way to reduce oxides in supercritical solutions near room temperature.

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Low-temperature synthesis and photoluminescence of AlN

Cited by 75 publications

References 17 publications

Optical properties of AlN thin films grown by plasma enhanced atomic layer deposition

Optical properties of AlN thin films grown by plasma enhanced atomic layer deposition

Aligned AlN Nanorods with Multi‐tipped Surfaces—Growth, Field‐Emission, and Cathodoluminescence Properties

Chemical Reduction of Nd_1.85Ce_0.15CuO_4−δPowders in Supercritical Sodium Ammonia Solutions

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Low-temperature synthesis and photoluminescence of AlN

Cited by 75 publications

References 17 publications

Optical properties of AlN thin films grown by plasma enhanced atomic layer deposition

Optical properties of AlN thin films grown by plasma enhanced atomic layer deposition

Aligned AlN Nanorods with Multi‐tipped Surfaces—Growth, Field‐Emission, and Cathodoluminescence Properties

Chemical Reduction of Nd1.85Ce0.15CuO4−δPowders in Supercritical Sodium Ammonia Solutions

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Chemical Reduction of Nd_1.85Ce_0.15CuO_4−δPowders in Supercritical Sodium Ammonia Solutions