Novel Co‐Doped Y 2 GeO 5 :Pr 3+ ,Tb 3+ : Deep Trap Level Formation and Analog Binary Optical Storage with Submicron Information Points

In this work, Mn[Formula: see text]Eu[Formula: see text] co-doped Zn2GeO4 (Zn2GeO4:Mn[Formula: see text] was prepared by high-temperature solid phase method. Compared with common fluorescent materials Zn2GeO4:Mn[Formula: see text], Zn2GeO4:Mn[Formula: see text] could not only emit strong green fluorescence of 535 nm, but also maintain excellent persistent luminescence performance. Through Density Functional Theory calculation, we obtained the fine band structure of Zn2GeO4:Mn[Formula: see text]. The results of the band structure were consistent with the experimental spectral data. On this basis, we proposed a new luminescence mechanism model of Zn2GeO4:Mn[Formula: see text] to explain the phenomena observed in experiment reasonably, though which was not completely consistent with previous works. When Zn2GeO4:Mn[Formula: see text] was excited, electron–hole separation occurred in the valence band (VB), and the electron transitioned to the conduction band (CB) directly. Through CB, the electron was trapped by trap levels (7F[Formula: see text]F5 of Eu[Formula: see text] and maintained metastable for a long time. Under the action of thermal stimulation, electron returned to CB from the trap level slowly. The electron was captured again by the 4T2(D) level of Mn[Formula: see text]. Then the electron transitioned down toward VB and recombined with the previous hole and emitted a photon with 535 nm (afterglow). The samples were being irradiated, trap levels accommodated the excited electrons to saturation. More electrons excited into the CB could not be captured by the trap levels any more. They were captured directly by the 4T2(D) and transitioned directly to VB, then emitted green fluorescence.

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Effect of deep-trap level on transverse acoustoelectric voltage measurements

IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control ◽

10.1109/58.84297 ◽

1991 ◽

Vol 38 (5) ◽

pp. 503-509 ◽

Cited By ~ 4

Author(s):

F. Palma ◽

G. de Cesare ◽

A. Abbate ◽

P. Das

Keyword(s):

Deep Trap ◽

Trap Level

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Luminescence Reducing Mechanism of Cd Doped Y2O2S:Ti,Cd Long Afterglow Phosphor

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.604 ◽

2007 ◽

Vol 336-338 ◽

pp. 604-606

Author(s):

Peng Yue Zhang ◽

Zhang Lian Hong ◽

Xian Ping Fan ◽

Min Quan Wang

Keyword(s):

Solid State ◽

Trap Depth ◽

Emission Peak ◽

Trap Level ◽

Structure Defect ◽

Photoluminescence Spectra ◽

Ion Content ◽

Long Afterglow ◽

Chromaticity Coordinate ◽

Co Doped

Y1.97-xTi0.03CdxO2S (0≤x≤0.06) phosphors with long afterglow were synthesized by solid-state reaction. The photoluminescence spectra, decay curves, thermoluminescnece spectra and Chromaticity coordinate curves were investigated. Results showed that the luminescence and afterglow intensity of Y1.97-xTi0.03CdxO2S (0≤x≤0.06) reduced gradually with increasing Cd2+ ion content while the shape and position of emission peak remain unchanged. The Chromaticity coordinate of present phosphor keeps at (0.5497,0.4415). Furthermore, based on the results of thermoluminescence curves of Ti, Cd single doped and co-doped Y2O2S phosphors, the doped Cd ion reduces the inherent trap depth of Ti single doped Y2O2S:Ti, and induces simultaneously a new trap level in Y2O2S:Ti,Cd phosphor. Thus, it was proposed that the introduced new structure defect by Cd2+ ions should be responsible for the reducing luminescence and afterglow property.

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Hydrogen Diffusion Mechanism in Amorphous Silicon From D Tracer Diffusion: Theory and Experiment

MRS Proceedings ◽

10.1557/proc-297-279 ◽

1993 ◽

Vol 297 ◽

Cited By ~ 5

Author(s):

Howard M. Branz ◽

Sally Asher ◽

Brent P. Nelson ◽

Mathieu Kemp

Keyword(s):

Hydrogen Diffusion ◽

Diffusion Mechanism ◽

Effective Diffusion ◽

Early Time ◽

Deep Trap ◽

Tracer Diffusion ◽

Release Time ◽

Decay Length ◽

Trap Level ◽

The Mean

We compare experimental diffusion studies to the results of a theoretical study of diffusion controlled by a single deep trap level. Analytic solutions for the D profiles after annealing depend on the characteristic H release time, τ, from the deep trap. At times much shorter than τ, the D profile develops exponential wings whose decay length is the mean D displacement between trapping events. The long-time D profile is a solution to the ideal diffusion equation, but with an effective diffusion coefficient that can be calculated from features of the early-time profiles. New experimental data establish the validity of the model at a range of anneal times and temperatures. We also find that the mean displacement of free H before retrapping decreases with both increased illumination and increasing anneal temperature.

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Profiling the Deep Trap Level in the Semiconductor Heterostructures by Small-Pulse Deep Level Transient Spectroscopy

MRS Proceedings ◽

10.1557/proc-338-195 ◽

1994 ◽

Vol 338 ◽

Author(s):

Zhang Rong ◽

Yang Kai ◽

Qing Guoyi ◽

Shi Yi ◽

Gu Shulin ◽

...

Keyword(s):

Deep Level ◽

Deep Trap ◽

Good Method ◽

Deep Levels ◽

Semiconductor Heterostructures ◽

Trap Level ◽

Narrow Gap ◽

Transient Spectroscopy ◽

First Time ◽

Doping Condition

ABSTRACTIn this paper we report for the first time theoretical and experimental study on smallpulse DLTS measurements of deep levels in semiconductor heterostructures. A theoretical model has been developed on the basis of the Schodinger and Poisson's electrostatic equation. Distribution of charge density in the superlattice has been considered, especially transferred charges in the “narrow gap” sublayers. The calculated results indicate that tinder the 1017/cm3 doping condition, a 30mV small pulse corresponds to a 2nm “sampling space window”, it is enough to detect special signal of deep levels in each sublayer in the semiconductor heterostructures. A SiGe/Si sample has been measured by the small-pulse DLTS. The experimental results agree well with the theoretical prediction and show that the small-pulse DLTS is a good method to study deep levels in the semiconductor heterostructures.

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The Luminous mechanism of Eu2+ and Dy3+ co-doped long persistent luminous fiber

Textile Research Journal ◽

10.1177/0040517518817056 ◽

2018 ◽

Vol 89 (17) ◽

pp. 3601-3609 ◽

Cited By ~ 2

Author(s):

Xuefeng Guo ◽

Keqin Zhang ◽

Mingqiao Ge

Keyword(s):

Decay Process ◽

Trap Level ◽

Luminescence Peak ◽

Time Extension ◽

Higher Temperature ◽

Set Up ◽

Best Fit ◽

Thermo Luminescence ◽

Co Doped ◽

Decay Behavior

Fiber-forming polymer polyethylene terephthalate chips were blended with Eu2+ and Dy3+ co-doped SrAl2O4 (SAOED) to afford luminous fiber with long and persistent afterglow. A dynamical model was set up to study the afterglow process in order to correlate the afterglow characteristics with the trap levels of SAOED and luminous fiber. The results indicated that the illustration of initial afterglow for luminous fiber was obviously lower than that of SAOED, but its decay process was moderately slow and therefore longer than that of SAOED. Compared with SAOED, the thermo-luminescence peak of the fiber shifted to the higher temperature, and its intensity was lower than that of SAOED. With the time extension of delay time after excitation, the depth of trap level for luminous fiber in our studies did not show any significant change. The afterglow decay behavior can be best fit by using I = I0/(1 + bt)2; the fitting showed that the afterglow decay process followed the second order dynamics.

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Annealing Behavior of Deep Trap Level in p-GaTe

Japanese Journal of Applied Physics ◽

10.1143/jjap.37.3282 ◽

1998 ◽

Vol 37 (Part 1, No. 6A) ◽

pp. 3282-3283 ◽

Cited By ~ 13

Author(s):

Shigeru Shigetomi ◽

Tetsuo Ikari ◽

Hiroshi Nakashima

Keyword(s):

Deep Trap ◽

Trap Level ◽

Annealing Behavior

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Visible light driven photocatalytic activity of Fe-doped ZnO nanocrystals

Functional Materials Letters ◽

10.1142/s1793604717500023 ◽

2017 ◽

Vol 10 (02) ◽

pp. 1750002 ◽

Cited By ~ 7

Author(s):

Bao-Gai Zhai ◽

Long Yang ◽

Qing-Lan Ma ◽

Yuan Ming Huang

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Density Functional ◽

Diffuse Reflectance Spectroscopy ◽

Deep Trap ◽

Precipitation Method ◽

Trap Level ◽

Zno Nanocrystals ◽

Visible Light Driven ◽

Doped Zno

Fe-doped ZnO nanocrystals at the level of 8[Formula: see text]mol% were synthesized via the co-precipitation method and then characterized by transmission electron microscopy, X-ray diffraction, diffuse reflectance spectroscopy and UV–Vis absorption spectroscopy. Strong absorptions with its peak at around 500[Formula: see text]nm were recorded in the range of 400–600[Formula: see text]nm for Fe-doped ZnO nanocrystals. Visible-light driven photocatalytic activity of Fe-doped ZnO nanocrystals was demonstrated via the photocatalytic degradation of methyl orange dye. Density functional calculations show that Fe dopant can generate a deep trap level at Ev [Formula: see text] 1.01[Formula: see text]eV in the bandgap of ZnO, which is believed to be responsible for the visible light responsive photocatalytic activity of Fe-doped ZnO.

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Observations in Changes of Electrical Properties in Thermally Neutron-Exposed Boron-Doped Silicon Semiconductors

Journal of Nuclear Engineering and Radiation Science ◽

10.1115/1.4029961 ◽

2015 ◽

Vol 1 (3) ◽

Author(s):

Hector E. Medina ◽

Brian Hinderliter

Keyword(s):

Electrical Properties ◽

Boron Concentration ◽

National Laboratory ◽

Radiation Detection ◽

Neutron Radiation ◽

Deep Trap ◽

Trap Level ◽

Boron Doped ◽

Before And After ◽

Electronic Parameters

Boron-doped resistors and transistors were developed using various levels of boron concentration. These were exposed to a thermal neutron flux of about 2×108 s−1 cm−2 at various fluences, at Los Alamos National Laboratory. Characterization of some electrical properties was carried out before and after irradiation. The reaction, 10B+n→Li+α, and others, caused by neutron irradiation, introduced impurities in the silicon lattice, thus producing measurable differences in electronic parameters. The results show that for irradiated resistors possessing very low values of boron concentration (≈1014 cm−3), there is a significant reduction (i.e., orders of magnitude) in resistivity, for the higher fluences studied (2×1011–1012 cm−2). This trend is not seen for high values of boron concentration (≈1021 cm−3), nor for the low-boron-concentration specimens exposed to a lower fluence. These observations appear to be in accordance with the deep-trap level behavior, and, though requiring further study, they seem to be promising for the potential application on neutron radiation detection. Additionally, there was no observation of significant changes in other electronic parameters, such as threshold voltage or trans-conductance, for the transistors exposed and tested.

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