scholarly journals Li 2 Eu 3 Br 2 [BO 3 ] 2 : A New Europium(II) Halide Oxoborate with Yellow Luminescence

2020 ◽  
Vol 646 (21) ◽  
pp. 1774-1781
Author(s):  
Jean‐Louis Hoslauer ◽  
Falk Lissner ◽  
Björn Blaschkowski ◽  
Thomas Schleid
Keyword(s):  
1995 ◽  
Vol 395 ◽  
Author(s):  
X. Zhang ◽  
P. Kung ◽  
D. Walker ◽  
A. Saxler ◽  
M. Razeghi

ABSTRACTWe report the growth and photoluminescence characterization of GaN grown on different substrates and under different growth conditions using metalorganic chemical vapor deposition. The deep-level yellow luminescence centered at around 2.2eV is attributed to native defect, most possibly the gallium vacancy. The yellow luminescence can be substantially reduced By growing GaN under Ga-rich condition or doping GaN with Ge or Mg.


2015 ◽  
Vol 33 (7) ◽  
pp. 712-716 ◽  
Author(s):  
Hiroaki Samata ◽  
Shungo Imanaka ◽  
Masashi Hanioka ◽  
Tadashi C. Ozawa
Keyword(s):  

1999 ◽  
Vol 595 ◽  
Author(s):  
Giancarlo Salviati ◽  
Nicola Armani ◽  
Carlo Zanotti-Fregonara ◽  
Enos Gombia ◽  
Martin Albrecht ◽  
...  

AbstractYellow luminescence (YL) has been studied in GaN:Mg doped with Mg concentrations ranging from 1019 to 1021 cm−3 by spectral CL (T=5K) and TEM and explained by suggesting that a different mechanism could be responsible for the YL in p-type GaN with respect to that acting in n-type GaN.Transitions at 2.2, 2.8, 3.27, 3.21, and 3.44 eV were found. In addition to the wurtzite phase, TEM showed a different amount of the cubic phase in the samples. Nano tubes with a density of 3×109 cm−2 were also observed by approaching the layer/substrate interface. Besides this, coherent inclusions were found with a diameter in the nm range and a volume fraction of about 1%.The 2.8 eV transition was correlated to a deep level at 600 meV below the conduction band (CB) due to MgGa-VN complexes. The 3.27 eV emission was ascribed to a shallow acceptor at about 170-190 meV above the valence band (VB) due to MgGa.The 2.2 eV yellow band, not present in low doped samples, increased by increasing the Mg concentration. It was ascribed to a transition between a deep donor level at 0.8-1.1 eV below the CB edge due to NGa and the shallow acceptor due to MgGa. This assumption was checked by studying the role of C in Mg compensation. CL spectra from a sample with high C content showed transitions between a C-related 200 meV shallow donor and a deep donor level at about 0.9- 1.1 eV below the CB due to a NGa-VN complex. In our hypothesis this should induce a decrease of the integrated intensity in both the 2.2 and 2.8 eV bands, as actually shown by CL investigations.


Author(s):  
R. Freitag ◽  
K. Thonke ◽  
R. Sauer ◽  
D. G. Ebling ◽  
L. Steinke

We report on the time-resolved luminescence of the defect-related violet band from undoped AlN epitaxial layers grown on sapphire and SiC. For both measurements in photoluminescence and in cathodoluminescence a decay of algebraic nature at long times is observed. This is typical for donor-acceptor pair transitions. We compare the behavior of this band to that of the generically yellow luminescence of GaN.


2007 ◽  
Vol 102 (11) ◽  
pp. 113521 ◽  
Author(s):  
D. G. Zhao ◽  
D. S. Jiang ◽  
J. J. Zhu ◽  
Z. S. Liu ◽  
S. M. Zhang ◽  
...  

2007 ◽  
Vol 62 (12) ◽  
pp. 1535-1542 ◽  
Author(s):  
Andreas Rief ◽  
Frank Kubel ◽  
Hans Hagemann

A new barium silico-aluminate phase with the stoichiometry Ba13.35(1) Al30.7Si5.3O70 has been found and characterized. The compound crystallizes in the space group P63/m (No. 176) with a = 15.1683(17), c = 8.8708(6) Å, V = 1767.5(4) Å3, Z = 1, Rw = 0.026, 32 refined parameters. A 3-dimensional matrix of Al/SiO4 tetrahedra with Ba(II) ions located in channels along the c axis builds up the structure. One of these channels is partially filled with Ba(II) ions (CN 6+3) in Wyckoff position 2a, leaving ~ 1/3 of the positions empty. The second and third type of Ba(II) ions occupy channels orientated along the c axis with CN 4+2+2 and 4+3+1, respectively. The structure shows a rare clustered arrangement of six tetrahedra filled exclusively by Al(III) and therefore is an exception to Loewenstein’s rule. The other tetrahedral positions show an Al to Si ratio of ~ 4 : 1. The Al/Si-O bond lengths in the tetrahedral Al/Si positions drawn vs. site occupation show linear behavior similar to the prediction by Vegard’s rule for solid solutions. After doping with Eu(II) the compound shows bright orange-yellow luminescence with an unusual large shift of the Eu(II) emission band.


2017 ◽  
Vol 864 ◽  
pp. 012016 ◽  
Author(s):  
Y. Torita ◽  
N. Nishikata ◽  
K. Kuriyama ◽  
K. Kushida ◽  
A. Kinomura ◽  
...  

2010 ◽  
Vol 97 (15) ◽  
pp. 152108 ◽  
Author(s):  
J. L. Lyons ◽  
A. Janotti ◽  
C. G. Van de Walle

1998 ◽  
Vol 537 ◽  
Author(s):  
E. E. Reuter ◽  
R. Zhang ◽  
T. F. Kuech ◽  
S. G. Bishop

AbstractWe have done a comparative study of carbon-doped GaN and undoped GaN utilizing photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies in order to investigate deep levels involved in yellow luminescence (YL) and red luminescence (RL). When the GaN was excited by above-bandgap light, red luminescence (RL) centered at 1.82 eV was the dominant below-gap PL from undoped GaN, but carbon-doped GaN below-gap PL was dominated by yellow luminescence (YL) centered at 2.2 eV. When exciting PL below the band-gap with 2.4 eV light, undoped GaN had a RL peak centered at 1.5 eV and carbon-doped GaN had a RL peak centered at 1.65 eV. PLE spectra of carbon-doped GaN, detecting at 1.56 eV, exhibited a strong, broad excitation band extending from about 2.1 to 2.8 eV with an unusual shape that may be due to two or more overlapping excitation bands. This RL PLE band was not observed in undoped GaN. We also demonstrate that PL spectra excited by below gap light in GaN films on sapphire substrates are readily contaminated by 1.6-1.8 eV and 2.1-2.5 eV chromium-related emission from the substrate. A complete characterization of the Cr emission and excitation bands for sapphire substrates enables the determination of the excitation and detection wavelengths required to obtain GaN PL and PLE spectra that are free of contributions from substrate emission.


2001 ◽  
Vol 79 (3) ◽  
pp. 281-283 ◽  
Author(s):  
Y. C. Chang ◽  
A. E. Oberhofer ◽  
J. F. Muth ◽  
R. M. Kolbas ◽  
R. F. Davis
Keyword(s):  

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