Electron Microprobe and Photoluminescence Analysis of Europium-Doped Gallium Nitride Light Emitters

2002 ◽  
Vol 743 ◽  
Author(s):  
R. W. Martin ◽  
S. Dalmasso ◽  
K. P. O'Donnell ◽  
Y. Nakanishi ◽  
A. Wakahara ◽  
...  

ABSTRACTRare-earth doped GaN structures offer potential for optical devices emitting in the visible region [1,2]. We describe a study of MOVPE grown GaN-on-sapphire epilayers implanted with Europium ions, producing characteristic red emission lines between 540 and 680 nm due to intra-4f(n) electron transitions. As-implanted and subsequently annealed samples are investigated using a combination of wavelength dispersive x-ray analysis (WDX), electron microscopy, cathodoluminescence (CL) and photoluminescence (PL). WDX is shown to be a powerful technique for quantifying rare-earth concentrations in GaN, with varying electron beam voltages allowing a degree of depth profiling, further enhanced by the simultaneous collection of room temperature luminescence (CL) from the analysed region [3]. The intensities of the sharp lines observed in the luminescence spectrum are compared to the doping density (between 1014 – 1015 cm−2) and the Eu content measured by WDX, using a Eu-doped glass standard. Differences observed in the luminescence spectra produced by laser and electron beam excitation will be discussed along with the importance of the annealing conditions, which “heal” defects visible in the electron micrographs.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wojciech A. Pisarski ◽  
Joanna Pisarska ◽  
Marta Kuwik ◽  
Marcin Kochanowicz ◽  
Jacek Żmojda ◽  
...  

AbstractFluoroindate glasses co-doped with Pr3+/Er3+ ions were synthesized and their near-infrared luminescence properties have been examined under selective excitation wavelengths. For the Pr3+/Er3+ co-doped glass samples several radiative and nonradiative relaxation channels and their mechanisms are proposed under direct excitation of Pr3+ and/or Er3+. The energy transfer processes between Pr3+ and Er3+ ions in fluoroindate glasses were identified. In particular, broadband near-infrared luminescence (FWHM = 278 nm) associated to the 1G4 → 3H5 (Pr3+), 1D2 → 1G4 (Pr3+) and 4I13/2 → 4I15/2 (Er3+) transitions of rare earth ions in fluoroindate glass is successfully observed under direct excitation at 483 nm. Near-infrared luminescence spectra and their decays for glass samples co-doped with Pr3+/Er3+ are compared to the experimental results obtained for fluoroindate glasses singly doped with rare earth ions.


2003 ◽  
Vol 798 ◽  
Author(s):  
S. Dalmasso ◽  
R. W. Martin ◽  
P. R. Edwards ◽  
V. Katchkanov ◽  
K. P. O'Donnell ◽  
...  

ABSTRACTGaN films doped with rare earth (RE) elements have attracted considerable attention due to the unique optical luminescent properties of the RE intra 4ƒ(n)-shell electron transitions which lead to sharp blue (Tm), green (Er) and red (Eu) emissions. This paper presents an overview of investigations of GaN films implanted with each of these ions using a combination of electron-beam and optical techniques. The ion implantations were performed under a wide range of conditions, covering variations in fluences, energies and temperatures and followed by different high-temperature annealing steps. The resulting RE:GaN films were analysed using an electron probe micro-analyser modified to allow cathodoluminescence (CL) spectroscopy. Elemental microanalysis data obtained by wavelength dispersive X-ray analysis (WDX) is correlated with simultaneously collected room temperature CL spectra.WDX allows the quantification of the RE elemental concentrations in GaN down to ∼ 0.03 at. % in very thin layers (∼ 100 nm deep). Furthermore, by varying the incident electron beam energy, details concerning the depth profile of RE implants can be determined. The effects of both implantation conditions and rapid thermal annealing on the depth profile and on the luminescence properties are reported. CL measurements performed on annealed samples reveal sharp visible and near IR emission lines characteristic of the RE3+ intra-4ƒ(n) atomic shell transitions.


2004 ◽  
Vol 43 (19) ◽  
pp. 3829 ◽  
Author(s):  
Lionel Aigouy ◽  
Yannick De Wilde ◽  
Michel Mortier ◽  
Jacques Giérak ◽  
Eric Bourhis

1986 ◽  
Vol 41 (6) ◽  
pp. 866-870 ◽  
Author(s):  
H.-D. Autenrieth ◽  
S. Kemmler-Sack

By activation of the new host lattices Ba2La2B2+Te2O12 (B = Zn, Mg) with trivalent rare earth ions Ln3+ = Pr. Sm, Eu, Tb, Dy, Ho, Tm an emission in the visible region is observed. The influence of the electronic structure and concentration on the relative emission efficiency as well as the host lattice participation in the energy transfer processes are discussed.


2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
J. Li ◽  
O. H. Y. Zalloum ◽  
T. Roschuk ◽  
C. L. Heng ◽  
J. Wojcik ◽  
...  

Rare earth (Tb or Ce)-doped silicon oxides were deposited by electron cyclotron resonance plasma-enhanced chemical vapour deposition (ECR-PECVD). Silicon nanocrystals (Si-ncs) were formed in the silicon-rich films during certain annealing processes. Photoluminescence (PL) properties of the films were found to be highly dependent on the deposition parameters and annealing conditions. We propose that the presence of a novel sensitizer in the Tb-doped oxygen-rich films is responsible for the indirect excitation of the Tb emission, while in the Tb-doped silicon-rich films the Tb emission is excited by the Si-ncs through an exciton-mediated energy transfer. In the Ce-doped oxygen-rich films, an abrupt increase of the Ce emission intensity was observed after annealing at 1200∘C. This effect is tentatively attributed to the formation of Ce silicate. In the Ce-doped silicon-rich films, the Ce emission was absent at annealing temperatures lower than 1100∘C due to the strong absorption of Si-ncs. Optimal film compositions and annealing conditions for maximizing the PL intensities of the rare earths in the films have been determined. The light emissions from these films were very bright and can be easily observed even under room lighting conditions.


2012 ◽  
Vol 568 ◽  
pp. 380-383
Author(s):  
Song Tian Li ◽  
Guo Xu He ◽  
Wei Ma ◽  
Yan Hua Liu

In order to expand photoresponse range of TiO2, reduce energy consumption of semiconductor material optical catalytic, certain amount of rare earth element Erbiun was doped during preparation of anatase titanium dioxide to improve the light absorption and photocatalysis efficiency. A series of rare earth element doped TiO2 material were prepared by sol-gel process, and characterized by means of UV-vis diffuse reflectance spectra. UV-vis absorption verified that doping of Er3+ enhanced absorptive capacity of catalyst in visible region. The photocatalytic performance of anatase titanium dioxide and rare earth element Erbiun doped with TiO2 to basic fuchsin were studied.


Author(s):  
S Dalmasso ◽  
R W Martin ◽  
P R Edwards ◽  
K P O'Donnell ◽  
B Pipeleers ◽  
...  

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 646
Author(s):  
Peng Jiang ◽  
Zhipeng Li ◽  
Wei Lu ◽  
Yi Ma ◽  
Wenhuai Tian

Developing rare-earth doped oxysulfide phosphors with diverse morphologies has significant value in many research fields such as in displays, medical diagnosis, and information storage. All of the time, phosphors with spherical morphology have been developed in most of the related literatures. Herein, by simply adjusting the pH values of the reaction solution, Gd2O2S:Tb3+ phosphors with various morphologies (sphere-like, sheet-like, cuboid-like, flat square-like, rod-like) were synthesized. The XRD patterns showed that phosphors with all morphologies are pure hexagonal phase of Gd2O2S. The atomic resolution structural analysis by transmission electron microscopy revealed the crystal growth model of the phosphors with different morphology. With the morphological change, the band gap energy of Gd2O2S:Tb3+ crystal changed from 3.76 eV to 4.28 eV, followed by different luminescence performance. The samples with sphere-like and cuboid-like microstructures exhibit stronger cathodoluminescence intensity than commercial product by comparison. Moreover, luminescence of Gd2O2S:Tb3+ phosphors have different emission performance excited by UV light radiation and an electron beam, which when excited by UV light is biased towards yellow, and while excited by an electron beam is biased towards cyan. This finding provides a simple but effective method to achieve rare-earth doped oxysulfide phosphors with diversified and tunable luminescence properties through morphology control.


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