scholarly journals Влияние ионов неодима (III) на фотолюминесценцию сульфидов кадмия и цинка в полиакрилатной матрице

2022 ◽  
Vol 56 (2) ◽  
pp. 229
Author(s):  
В.П. Смагин ◽  
А.А. Исаева ◽  
Е.А. Шелепова
Keyword(s):  
Methyl Methacrylate ◽  
Valence Band ◽  
Conduction Band ◽  
Structural Defects ◽  
Excitation Spectra ◽  
Nanoscale Particles ◽  
Semiconductor Structures ◽  
Semiconductor Particles ◽  
Optically Transparent

Nanoscale particles ZnS:Nd3+, CdS:Nd3+ and (Zn,Cd)S:Nd3+ were synthesized and doped in a polymerizing methyl methacrylate medium during the production of optically transparent polyacrylate composites of the composition PMMA/ZnS:Nd3+, PMMA/CdS:Nd3+ and PMMA/(Zn,Cd)S:Nd3+. The excitation of photoluminescence (FL) and FL of semiconductor structures in composites is associated with the transition of electrons from the valence band to the conduction band and to the levels of structural defects of semiconductor particles, followed by recombination at these levels. Based on changes in the excitation spectra of FL and FL composites, assumptions are made about the structure of particles, the distribution of Nd3+ ions in it and their effect on photoluminescence.

scholarly journals Фотолюминесценция низкоразмерных композитных структур полиметилметакрилат/(Zn,Cd,Mn,Eu)S

2021 ◽  
Vol 91 (5) ◽  
pp. 808
Author(s):  
В.П. Смагин ◽  
А.А. Исаева
Keyword(s):  
Energy Transfer ◽  
Band Gap ◽  
Valence Band ◽  
Energy Levels ◽  
Structural Defects ◽  
Photoluminescence Excitation ◽  
Semiconductor Particles ◽  
Optically Transparent ◽  
Partial Energy ◽  
Low Dimensional

A colloidal technology for the synthesis and doping of low-dimensional structures based on zinc and cadmium sulfides directly in the medium of an acrylic monomer is implemented in the process of obtaining optically transparent compositions of polymethylmethacrylate/(Zn,Cd,Mn,Eu)S. It is shown that the photoluminescence of the compositions is associated with a system of levels of structural defects of semiconductor particles located in its band gap, which are formed during successive doping of ZnS and CdS layers with Mn2+ and Eu3+ ions, and with intraband 5D0 → 7F1,2,4 transitions of 4f-electrons of Eu3+ ions. Photoluminescence excitation it occurs as a result of the transition of electrons from the valence band of a semiconductor to the levels of defects in its structure and partial energy transfer to the excited energy levels of Eu3+ ions.

Photoluminescence and Photoluminescence Excitation Spectra of GaAs Grown Directly on Si

1986 ◽  
Vol 67 ◽  
Author(s):  
S. Zemon ◽  
S. K. Shastry ◽  
P. Norris ◽  
C. Jagannath ◽  
G. Lambert
Keyword(s):  
High Temperature ◽  
Valence Band ◽  
Conduction Band ◽  
Tensile Strain ◽  
Second Line ◽  
Photoluminescence Excitation ◽  
Excitation Spectra ◽  
Biaxial Tensile ◽  
Band Transition ◽  
Biaxial Tensile Strain

ABSTRACTThe photoluminescence of GaAs/Si grown by OMCVD has been analyzed as a function of temperature and the dominant high temperature line identified as a conduction-band-to-valence-band transition. Photoluminescence excitation spectra indicate that the transition is excitonic at 4.2 K. A second line, also identified as intrinsic, dominates the spectra below 100 K. A biaxial tensile strain is proposed to account for the two intrinsic lines through a splitting of the valence band degeneracy.

scholarly journals Фотолюминесценция композитов полиметилметакрилат / [(Zn,Cd)S : Mn,Cu,Eu]

2021 ◽  
Vol 47 (16) ◽  
pp. 46
Author(s):  
В.П. Смагин ◽  
А.А. Исаева
Keyword(s):  
Energy Transfer ◽  
Methyl Methacrylate ◽  
Interband Transition ◽  
Energy Levels ◽  
Structural Defects ◽  
Nanoscale Structures ◽  
Semiconductor Structures ◽  
Electron Transitions ◽  
Recombination Processes ◽  
Defect Levels

Nanoscale structures based on zinc and cadmium sulfides doped with Mn, Cu, and Eu ions were synthesized by the method of emerging reagents in a polymerizing medium of methyl methacrylate. The broadband photoluminescence of the compositions is associated with recombination processes at the defect levels of semiconductor structures. Narrow photoluminescence bands occur during electron transitions between the energy levels of Eu3+ ions. The excitation of photoluminescence occurs as a result of the interband transition and electron transitions to the levels of structural defects, as well as during self-absorption and energy transfer to the levels of Eu3+ ions.

scholarly journals Conduction Band Engineering of Half-Heusler Thermoelectrics Using Orbital Chemistry

2022 ◽  
Author(s):  
Shuping Guo ◽  
Shashwat Anand ◽  
Madison K. Brod ◽  
Yongsheng Zhang ◽  
G. Jeffrey Snyder
Keyword(s):  
Electronic Properties ◽  
Valence Band ◽  
Conduction Band ◽  
Thermoelectric Materials ◽  
Band Engineering

Semiconducting half-Heusler (HH, XYZ) phases are promising thermoelectric materials owing to their versatile electronic properties. Because the valence band of half-Heusler phases benefits from the valence band extrema at several...

POLARIZATION PROPERTIES OF SYNCHROTRON RADIATION IN THE STUDY OF ANISOTROPIC INSULATING CRYSTALS

2002 ◽  
Vol 09 (01) ◽  
pp. 469-472
Author(s):  
V. N. KOLOBANOV ◽  
I. A. KAMENSKIKH ◽  
V. V. MIKHAILIN ◽  
I. N. SHPINKOV ◽  
D. A. SPASSKY ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Energy Transfer ◽  
Synchrotron Radiation ◽  
Valence Band ◽  
Conduction Band ◽  
Electronic States ◽  
Absorption Region ◽  
New Information ◽  
Fundamental Absorption Region

The optical properties of a wide series of the tungstates with the scheelite and wolframite crystal structure at the threshold of the fundamental absorption region were studied. New information about the influence of the electronic states forming the bottom of the conduction band and the top of the valence band on the formation of emission centers and mechanisms of energy transfer to these centers was obtained.

Photophysics of Ceramic Luminophores. Zeolite-Based Luminophores of the Types Zn2SiO4: Mn and (CdO)2B2O3: Mn

1989 ◽  
Vol 44 (5) ◽  
pp. 557-559 ◽  
Author(s):  
K. Hesse ◽  
G. Gliemann ◽  
A. Kiss ◽  
P. Kleinschmit ◽  
W. Völker
Keyword(s):  
Emission Spectra ◽  
Structural Defects ◽  
Trap States ◽  
Host Crystal ◽  
Excitation Spectra

The emission spectra (at T = 10 K and 296 K) and the excitation spectra (at T = 295 K) of zeolite-based luminophores of the types Zn2SiO4:Mn and (CdO)2B2O3:Mn show the characteristics of Mn2+ in tetrahedral and octahedral surroundings, respectively, as well as additional features due to impurities and/or structural defects of the host crystal. The ZnSiO4⁻type phosphor exhibits photostimulated emission, which can be assigned to trap states of the silicate host.

scholarly journals Photocatalytic properties of a new Z-scheme system BaTiO3/In2S3 with a core–shell structure

RSC Advances ◽  
2019 ◽  
Vol 9 (20) ◽  
pp. 11377-11384 ◽  
Author(s):  
Kaili Wei ◽  
Baolai Wang ◽  
Jiamin Hu ◽  
Fuming Chen ◽  
Qing Hao ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Valence Band ◽  
Conduction Band ◽  
Shell Structure ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Core Shell ◽  
Valence Band Edge ◽  
Core Shell Structure ◽  
Positive Valence

It's highly desired to design an effective Z-scheme photocatalyst with excellent charge transfer and separation, a more negative conduction band edge (ECB) than O2/·O2− (−0.33 eV) and a more positive valence band edge (EVB) than ·OH/OH− (+2.27 eV).

Microscopic calculation of valence-band states in semiconductor structures in the presence of a magnetic field

1996 ◽  
Vol 54 (20) ◽  
pp. 14623-14632 ◽  
Author(s):  
W.-C. Tan ◽  
J. C. Inkson ◽  
G. P. Srivastava
Keyword(s):  
Magnetic Field ◽  
Valence Band ◽  
Microscopic Calculation ◽  
Semiconductor Structures
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