Layer number dependent optical properties of multilayer hexagonal BN epilayers

2017 ◽  
Vol 110 (9) ◽  
pp. 092102 ◽  
Author(s):  
X. Z. Du ◽  
M. R. Uddin ◽  
J. Li ◽  
J. Y. Lin ◽  
H. X. Jiang
Keyword(s):  
Optical Properties ◽  
Layer Number

Layer-Number Dependent Optical Properties of 2D Materials and Their Application for Thickness Determination

2017 ◽  
Vol 27 (19) ◽  
pp. 1604468 ◽  
Author(s):  
Xiao-Li Li ◽  
Wen-Peng Han ◽  
Jiang-Bin Wu ◽  
Xiao-Fen Qiao ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Optical Properties ◽  
2D Materials ◽  
Layer Number ◽  
Thickness Determination

scholarly journals Layer-number dependent and structural defect related optical properties of InSe

RSC Advances ◽  
2017 ◽  
Vol 7 (87) ◽  
pp. 54964-54968 ◽  
Author(s):  
T. Zheng ◽  
Z. T. Wu ◽  
H. Y. Nan ◽  
Y. F. Yu ◽  
A. Zafar ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electron Beam ◽  
Structural Defect ◽  
Electron Beam Irradiation ◽  
Beam Irradiation ◽  
Layer Number ◽  
Excitonic States

We present systematic investigations on the layer-dependent optical properties of InSe and modify its excitonic states by electron beam irradiation.

scholarly journals Electronic and Optical Properties of Two-Dimensional Tellurene: From First-Principles Calculations

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1075 ◽  
Author(s):  
David K. Sang ◽  
Bo Wen ◽  
Shan Gao ◽  
Yonghong Zeng ◽  
Fanxu Meng ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Density Functional ◽  
Energy Gap ◽  
Quantum Confinement Effect ◽  
Full Potential ◽  
Two Dimensional ◽  
Electronic And Optical Properties ◽  
Layer Number ◽  
Layer Structures

Tellurene is a new-emerging two-dimensional anisotropic semiconductor, with fascinating electric and optical properties that differ dramatically from the bulk counterpart. In this work, the layer dependent electronic and optical properties of few-layer Tellurene has been calculated with the density functional theory (DFT). It shows that the band gap of the Tellurene changes from direct to indirect when layer number changes from monolayer (1 L) to few-layers (2 L–6 L) due to structural reconstruction. Tellurene also has an energy gap that can be tuned from 1.0 eV (1 L) to 0.3 eV (6 L). Furthermore, due to the interplay of spin–orbit coupling (SOC) and disappearance of inversion symmetry in odd-numbered layer structures resulting in the anisotropic SOC splitting, the decrease of the band gap with an increasing layer number is not monotonic but rather shows an odd-even quantum confinement effect. The optical results in Tellurene are layer dependent and different in E ⊥ C and E || C directions. The correlations between the structure, the electronic and optical properties of the Tellurene have been identified. Despite the weak nature of interlayer forces in their structure, their electronic and optical properties are highly dependent on the number of layers and highly anisotropic. These results are essential in the realization of its full potential and recommended for experimental exploration.

scholarly journals Characterization of Layer Number of Two-Dimensional Transition Metal Diselenide Semiconducting Devices Using Si-Peak Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Xian Zhang
Keyword(s):  
Raman Spectroscopy ◽  
Optical Properties ◽  
Transition Metal ◽  
Nondestructive Method ◽  
Two Dimensional ◽  
Bandgap Engineering ◽  
Layer Number ◽  
Ambipolar Behavior ◽  
Molybdenum Diselenide

Atomically thin materials such as semiconducting transition metal diselenide materials, like molybdenum diselenide (MoSe2) and tungsten diselenide (WSe2), have received intensive interests in recent years due to their unique electronic structure, bandgap engineering, ambipolar behavior, and optical properties and have motivated investigations for the next-generation semiconducting electronic devices. In this work, we show a nondestructive method of characterizing the layer number of two-dimensional (2-D) MoSe2 and WSe2 including single- and few-layer materials by Raman spectroscopy. The related photoluminescence properties are also studied as a reference. Although Raman spectroscopy is a powerful tool for determining the layer number of 2-D materials such as graphene and molybdenum disulfide (MoS2), there have been difficulties in precisely characterizing the layer number for MoSe2 and WSe2 by Raman spectroscopy due to the uncertain shifts during the Raman measurement process and the lack of multiple separated Raman peaks in MoSe2 and WSe2 for referencing. We then compared the normalized Si peak with MoSe2 and WSe2 and successfully identified the layer number of MoSe2 and WSe2. Similar to graphene and MoS2, the sample layer number is found to modify their optical properties up to 4 layers.

Layer number dependence of the work function and optical properties of single and few layers MoS2: effect of substrate

2019 ◽  
Vol 30 (24) ◽  
pp. 245708 ◽  
Author(s):  
Magdalena Tamulewicz ◽  
Joanna Kutrowska-Girzycka ◽  
Krzysztof Gajewski ◽  
Jarosław Serafińczuk ◽  
Andrzej Sierakowski ◽  
...  
Keyword(s):  
Optical Properties ◽  
Work Function ◽  
Layer Number

Layer-dependent optoelectronic properties of black phosphorus

2020 ◽  
Vol 31 (12) ◽  
pp. 2050177
Author(s):  
H. M. Dong ◽  
L. S. Huang ◽  
J. L. Liu ◽  
F. Huang ◽  
C. X. Zhao
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Uv Light ◽  
Decisive Role ◽  
Black Phosphorus ◽  
Optoelectronic Properties ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
Layer Number ◽  
Optical Responses

The layer-dependent optoelectronic properties of monolayer, bilayer and trilayer black phosphorus (BP) are studied by using the first-principles calculations based on density functional theory (DFT). The valence band splits and the density of states (DOS) in the conduction band obviously shift to the Fermi surface with the increased layer number. The atomic p orbital of BP plays an decisive role in determining the electronic and optical properties, which are drastically different from those of graphene and transition metal dichalogenides (TMDs). The increase of the layer number leads to the metal characteristics. The extinction coefficient and photoconductivity show strong optical responses to the ultraviolet (UV) light, which further increase with the number of layers. BP layers can reflect UV rays effectively because of their metallic properties in the UV energy range. Our study shows that the interlayer interaction can intensely change the electronic and optical properties of BP.

scholarly journals Effects of CdSe Layer Number on the Optical Properties and Microstructures of CdTe/CdSe (II) Core/Shell Quantum Dots

2012 ◽  
Vol 28 (01) ◽  
pp. 232-238
Author(s):  
PENG Jing ◽  
◽  
FANG Xiao-Ming ◽  
CHEN Zhi-Hong ◽  
ZHANG Zheng-Guo
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Core Shell ◽  
Layer Number ◽  
Cdse Layer

Design of objective lens for 200-kV high-resolution electron microscopes

1983 ◽  
Vol 41 ◽  
pp. 314-315
Author(s):  
K. Tsuno ◽  
T. Honda ◽  
Y. Harada ◽  
M. Naruse
Keyword(s):  
Optical Properties ◽  
Computer Technology ◽  
Axial Magnetic Field ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Resolution Electron ◽  
Correction Of Astigmatism ◽  
Three Stages ◽  
Electron Microscopes ◽  
Stage 1

Developement of computer technology provides much improvements on electron microscopy, such as simulation of images, reconstruction of images and automatic controll of microscopes (auto-focussing and auto-correction of astigmatism) and design of electron microscope lenses by using a finite element method (FEM). In this investigation, procedures for simulating the optical properties of objective lenses of HREM and the characteristics of the new lens for HREM at 200 kV are described.The process for designing the objective lens is divided into three stages. Stage 1 is the process for estimating the optical properties of the lens. Firstly, calculation by FEM is made for simulating the axial magnetic field distributions Bzc of the lens. Secondly, electron ray trajectory is numerically calculated by using Bzc. And lastly, using Bzc and ray trajectory, spherical and chromatic aberration coefficients Cs and Cc are numerically calculated. Above calculations are repeated by changing the shape of lens until! to find an optimum aberration coefficients.

Optical Properties of HVEM Accelerators

1975 ◽  
Vol 33 ◽  
pp. 180-181
Author(s):  
A. Strojnik ◽  
J.W. Scholl ◽  
V. Bevc
Keyword(s):  
Optical Properties ◽  
Electron Accelerator ◽  
Systematic Investigation ◽  
Electron Source ◽  
High Brightness ◽  
The Past ◽  
Wide Range ◽  
Optical Behavior

The electron accelerator, as inserted between the electron source (injector) and the imaging column of the HVEM, is usually a strong lens and should be optimized in order to ensure high brightness over a wide range of accelerating voltages and illuminating conditions. This is especially true in the case of the STEM where the brightness directly determines the highest resolution attainable. In the past, the optical behavior of accelerators was usually determined for a particular configuration. During the development of the accelerator for the Arizona 1 MEV STEM, systematic investigation was made of the major optical properties for a variety of electrode configurations, number of stages N, accelerating voltages, 1 and 10 MEV, and a range of injection voltages ϕ0 = 1, 3, 10, 30, 100, 300 kV).

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