Luminescence Due to Mn Doped GaP

1989 ◽  
Vol 163 ◽  
Author(s):  
Teresa Monteiro ◽  
Estela Pereira
Keyword(s):  
Ground State ◽  
Near Infrared ◽  
Thermal Quenching ◽  
Radiative Process ◽  
Mn Doped

AbstractIn n-type GaP doping with Mn gives rise to a deep centre due to Mn+2. Its luminescence occurs in the near infrared.The behaviour of this centre is studied as a function of temperature and the thermal quenching of the luminescence interpreted as due to a non-radiative process to the ground state. The behaviour of another band that appears upon doping with Mn is also discussed.

Two-photon absorption spectra of a near-infrared 2-azaazulene polymethine dye: solvation and ground-state symmetry breaking

2013 ◽  
Vol 15 (20) ◽  
pp. 7666 ◽  
Author(s):  
Honghua Hu ◽  
Olga V. Przhonska ◽  
Francesca Terenziani ◽  
Anna Painelli ◽  
Dmitry Fishman ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Absorption Spectra ◽  
Ground State ◽  
Near Infrared ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Polymethine Dye

Tuning the Electrochemical and Photophysical Properties of Osmium-Based Photoredox Catalysts

Synlett ◽  
2022 ◽  
Author(s):  
Eva Bednářová ◽  
Logan R. Beck ◽  
Tomislav Rovis ◽  
Samantha L. Goldschmid ◽  
Katherine Xie ◽  
...  
Keyword(s):  
Ground State ◽  
Emission Spectroscopy ◽  
Near Infrared ◽  
Photophysical Properties ◽  
Low Energy ◽  
Redox Potentials ◽  
Nir Light ◽  
Osmium Complexes ◽  
Absorption And Emission Spectroscopy

AbstractThe use of low-energy deep-red (DR) and near-infrared (NIR) light to excite chromophores enables catalysis to ensue across barriers such as materials and tissues. Herein, we report the detailed photophysical characterization of a library of OsII polypyridyl photosensitizers that absorb low-energy light. By tuning ligand scaffold and electron density, we access a range of synthetically useful excited state energies and redox potentials.1 Introduction1.1 Scope1.2 Measuring Ground-State Redox Potentials1.3 Measuring Photophysical Properties1.4 Synthesis of Osmium Complexes2 Properties of Osmium Complexes2.1 Redox Potentials of Os(L)2-Type Complexes2.2 Redox Potentials of Os(L)3-Type Complexes2.3 UV/Vis Absorption and Emission Spectroscopy3 Conclusions

Thermally boosted upconversion and downshifting luminescence in Sc2(MoO4)3:Yb/Er with two-dimensional negative thermal expansion

2021 ◽  
Author(s):  
Jinsheng Liao ◽  
Minghua Wang ◽  
Fulin Lin ◽  
Zhuo Han ◽  
Datao Tu ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Near Infrared ◽  
Negative Thermal Expansion ◽  
Thermal Quenching ◽  
Relative Sensitivity ◽  
Strong Temperature Dependence ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Higher Temperature

Abstract Lanthanide (Ln3+)-doped phosphors generally suffer from thermal quenching, in which their photoluminescence (PL) intensities decrease at the higher temperature. Herein, we report a class of unique two-dimensional negative-thermal-expansion phosphor of Sc2(MoO4)3:Yb/Er. By virtue of the reduced distances between sensitizers and emitters as well as confined energy migration with increasing the temperature, a 45-fold enhancement of green upconversion (UC) luminescence and a 450-fold enhancement of near-infrared downshifting (DS) luminescence of Er3+ are achieved from 25 to 500 ˚C. The thermally boosted UC and DS luminescence mechanism is systematically investigated through in situ temperature-dependent Raman spectroscopy, synchrotron X-ray diffraction and PL dynamics. Moreover, the luminescence lifetime of 4I11/2 of Er3+ in Sc2(MoO4)3:Yb/Er displays a strong temperature dependence, enabling ratiometric thermometry with the highest relative sensitivity of 13.4%/K at 298 K. These findings may gain a vital insight into the design of negative-thermal-expansion Ln3+-doped phosphors for versatile applications.

Synthesis and Characterization of Novel Platinum Acetylide Oligomers

2003 ◽  
Vol 771 ◽  
Author(s):  
Thomas M. Cooper ◽  
Benjamin C. Hall ◽  
Daniel G. McLean ◽  
Joy E. Rogers ◽  
Aaron R. Burke ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Ground State ◽  
Near Infrared ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Structure Property ◽  
Ground State Absorption ◽  
Excitation Spectra ◽  
C Nmr

AbstractAs part of an effort to develop a spectroscopic structure-property relationship in platinum acetylide oligomers, we have prepared a series of bidentate Pt(PBu3)2L2 compounds. The ligand was the series o-syd-C6H4-CΞC-(C6H4-CΞC)n-H, n = 0,1,2. The terminal oligomer unit consisted of a sydnone group ortho to the acetylene carbon. The compounds were characterized by various methods, including 13C-NMR, ground state absorption, fluorescence, phosphorescence and laser flash photolysis. The acetylenic 13C-NMR resonances showed sydnone influences that decreased with increasing number of monomer units. The ground state absorption spectra were slightly red shifted from those of the baseline oligomers not having a sydnone group. The low temperature emission and excitation spectra showed complex dependence on excitation and emission wavelengths, suggesting the chromphores resided in a distribution of solvent environments and conformations. Finally, broad triplet state absorption spectra were observed, with absorption throughout the visible and near infrared regions.

Etude à basse température dans l'infrarouge proche du dimère (NO)2

1984 ◽  
Vol 62 (4) ◽  
pp. 322-329 ◽  
Author(s):  
V. Menoux ◽  
R. Le Doucen ◽  
C. Haeusler ◽  
J. C. Deroche
Keyword(s):  
Excited State ◽  
Gas Phase ◽  
Ground State ◽  
Near Infrared ◽  
Heat Of Formation ◽  
Wave Number ◽  
Vibrational Modes ◽  
Vibrationally Excited ◽  
Rotational Constants ◽  
Absorption Intensity

The spectrum of the dimer (NO)2 in the gas phase has been studied in the near infrared at temperatures between 118 and 138 K. More specifically, the measure of absorption intensity of the ν4 and ν1 + ν4 bands has yielded the heat of formation of the dimer, −2.25 kcal/mol at 128 K, and revealed the influence of the low vibrational modes on this measure. The observation of the ν4 – ν6, difference band has yielded the wave number value of the ν6, fundamental band, forbidden in the infrared. The rotational constants of the vibrationally excited state were found to be larger than the ground state rotational constants, this result being very unusual.

scholarly journals Eco-friendly Mn-doped CsPbCl3 Perovskite Nanocrystals Glass with Blue-red Emitting for Indoor Plant Lighting

2020 ◽  
Author(s):  
Ya Chen ◽  
Linli Shen ◽  
Jianming Liu ◽  
Xiaojuan Liang ◽  
Weidong Xiang ◽  
...  
Keyword(s):  
Thermal Quenching ◽  
Light Emitting ◽  
Perovskite Nanocrystals ◽  
Plant Cultivation ◽  
Light Requirements ◽  
Fluorescent Materials ◽  
In Situ Crystallization ◽  
New Generation ◽  
Mn Doped

Abstract Mn-doped CsPbCl3 perovskite nanocrystals (PeNCs) glass was prepared by melt-quenching and in-situ crystallization. Under the protection of robust glass, PeNCs exhibit excellent moisture resistance and thermal stability. Due to the combination effect of thermal quenching and energy transfer of exciton-to-Mn2+, the emission intensity of Mn shows an abnormal temperature-dependence with the temperature increasing from 80 to 300 K, which can be explored further in the application of temperature sensor. Interestingly, by matching with ultraviolet chips, all-inorganic blue-red emitting conversion device consisting of PeNCs glasses were prepared for light-emitting diodes (LEDs), which can meet the light requirements of plant growth. The cultivation results indicated that growth of cabbages using PeNCs plant cultivation LEDs were greater than those cultivated using commercial w-LEDs. Therefore, Mn-doped CsPbCl3 PeNCs can be used as a new-generation of solid fluorescent materials in the field of indoor plant cultivation LEDs.

scholarly journals Absorption Spectrum of Ni(II) Ions Doped in Magnesium Thallium Sulphate Hexahydrate

1992 ◽  
Vol 47 (7-8) ◽  
pp. 813-818 ◽  
Author(s):  
A. Venkata Subbaiah ◽  
J. Lakshmana Rao ◽  
R. Murali Krishna ◽  
S. V. J. Lakshman
Keyword(s):  
Absorption Spectrum ◽  
Liquid Nitrogen ◽  
Ground State ◽  
Near Infrared ◽  
Liquid Nitrogen Temperature ◽  
Infrared Region ◽  
Orbit Splitting ◽  
Excited Triplet ◽  
Spin Orbit Splitting ◽  
Near Infrared Region

Abstract The optical absorption spectrum of Ni(II) ions doped in magnesium thallium sulphate hexahydrate has been studied at room- and liquid nitrogen-temperature. The crystal shows characteristic absorption of Ni(II) ion in the visible and near infrared region. The observed bands are assigned as transitions from the ground state 3A2g(F) to various excited triplet and singlet levels of the Ni(II) ion in octahedral symmetry. The splitting in one of the bands at liquid nitrogen temperature has been explained to be due to spin-orbit splitting. All the observed band positions have been fitted with the parameters B, C, Dq, and ξ

Spectroscopic and magnetic investigations of a spin-frustrated Mn-doped CoAl2O4 spinel

2019 ◽  
Vol 21 (2) ◽  
pp. 842-850 ◽  
Author(s):  
Suman Kalyan Pradhan ◽  
Biswajit Dalal ◽  
Ankita Sarkar ◽  
Subodh Kumar De
Keyword(s):  
Spin Glass ◽  
Ground State ◽  
Magnetic Ground State ◽  
Mn Concentration ◽  
Mn Doped

The magnetic ground state is transformed from collinear antiferromagnetic to spin-glass-like to cluster-glass-like with the increase of Mn concentration.

scholarly journals Multimodal Mn-doped I–III–VI quantum dots for near infrared fluorescence and magnetic resonance imaging: from synthesis to in vivo application

Nanoscale ◽  
2014 ◽  
Vol 6 (15) ◽  
pp. 9264-9272 ◽  
Author(s):  
Gary Sitbon ◽  
Sophie Bouccara ◽  
Mariana Tasso ◽  
Aurélie Francois ◽  
Lina Bezdetnaya ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Quantum Dots ◽  
Magnetic Resonance ◽  
Fluorescence Imaging ◽  
Near Infrared ◽  
Resonance Imaging ◽  
Near Infrared Fluorescence ◽  
Nir Fluorescence ◽  
Mn Doped

Cadmium-free quantum dots doped with Mn2+ions show promising results forin vivobimodal MRI and NIR fluorescence imaging.

Er-Related Emission In Impurities (Nitrogen, Oxygen) Implanted Al0.7Ga0.3As

1997 ◽  
Vol 484 ◽  
Author(s):  
S. Uekusa ◽  
M. Wakutani ◽  
M. Saito ◽  
M. Kumagai
Keyword(s):  
Excited State ◽  
Band Gap ◽  
Ground State ◽  
Thermal Quenching ◽  
Trap Level ◽  
Pl Intensity ◽  
Complex Center

AbstractErbium (Er) was co-implanted with ( i ) nitrogen (N), ( ii) oxygen (0) and (iii) N and 0 into Al0.7Ga0.3As substrates. Compared with the Al0.7Ga0.3As:Er sample, the 20 K Er3+ -related 1.54 μm integrated photoluminescence (PL) intensity from the Al0 7Ga0.3As:Er,N and Al0.7Ga0.3As:Er,N,O samples were enhanced approximately fifteen and ten times more, respectively. Thermal quenching of Er3+-related emission from Al0.7Ga0.3As:Er,N,O was smaller than that of Er3+-related emission from Al0.7.Ga0.3As-Er,N The 20 K Er3+-related 0.98 μm PL which was radiated by transition from the second excited state (4I1/2) to the ground state (4I1/2) was observed. The 0.98 μm PL intensity from Al0.7Ga0.3As:Er,N,O generally decreased with increasing 0 dosage from 1 × 1013 cm−2 to 1 × 1015 cm−2. These results suggest the formation of different complexes composed of Er and the impurities (N,O). This leads to the generation of complex related traps in the band-gap of Al0.7Ga0.3As as a result of the co-implantation of the impurities. It was found that the trap level of the Er-N complex center lay between 2.05 eV and 1.26 eV, and that of the Er-N-O complex center lay between 1.26 eV and 0.82 eV.

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