Modulation of the band structures and optical properties of holey C2N nanosheets by alloying with group IV and V elements

Group-IV monochalcogenides, such as germanium selenide (GeSe) are strongly anisotropic semiconducting van der Waals crystals isoelectronic to black phosphorus, with superior stability in air conditions. High optical absorption, good conductivity,...

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Tuning band gap and optical properties of SnX2 nanosheets: Hybrid functional studies

Modern Physics Letters B ◽

10.1142/s0217984916501207 ◽

2016 ◽

Vol 30 (10) ◽

pp. 1650120 ◽

Cited By ~ 2

Author(s):

P. Guo ◽

Y. W. Luo ◽

Y. Jia

Keyword(s):

Optical Properties ◽

Optical Absorption ◽

Band Gap ◽

Electronic Structures ◽

Threshold Values ◽

Hybrid Functional ◽

Functional Studies ◽

Quantum Size ◽

Light Activity ◽

Optical Applications

Based on hybrid functional calculations, the electronic structures and optical properties are investigated in the monolayer and bilayer tin dichalcogenides SnX2 (X = S and Se) nanosheets. Numerical results show that quantum size effects are obvious on the electronic structures and optical absorption in the SnS2 and SnSe2 nanosheets. The band gap values increase when the nanosheets layer numbers decrease. Moreover, for SnSe2 nanosheet, the optical absorption coefficients are high and its threshold values lie in the visible light activity range. These results are interesting and indicate that SnS2 and SnSe2 nanosheets may serve as the promising candidates for visible optical applications.

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Electronic and optical properties of CsPb2Br5: A first-principles study

Modern Physics Letters B ◽

10.1142/s021798491950266x ◽

2019 ◽

Vol 33 (22) ◽

pp. 1950266 ◽

Cited By ~ 1

Author(s):

Mingge Jin ◽

Zhibing Li ◽

Feng Huang ◽

Weiliang Wang

Keyword(s):

Optical Properties ◽

Optical Absorption ◽

Visible Light ◽

Band Gap ◽

First Principles ◽

First Principles Calculations ◽

Hybrid Functional ◽

Electronic And Optical Properties ◽

Optical Absorbance ◽

Indirect Band Gap

There are conflicting understandings of the electronic and optical properties of CsPb2Br5. We investigated the electronic and optical properties of CsPb2Br5 with first-principles calculations. It is confirmed that CsPb2Br5 is a semiconductor with an indirect band gap of 3.08 eV at GGA/PBE level and 3.72 eV at the HSE06 hybrid functional level. The PBE results demonstrate that the inclusion of SOC slightly reduces the band gap. We calculate the optical absorbance/emission spectrum of CsPb2Br5. It is found the optical absorption edges locate at 360–380 nm, shorter than the wavelength of visible light. Our results support the experimental results of Li et al. [Chem. Commun. 52 (2016) 11296] and Zhang et al. [J. Mater. Chem. C 6 (2018) 446].

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Novel electronic and optical properties of ultrathin silicene/arsenene heterostructures and electric field effects

Physical Chemistry Chemical Physics ◽

10.1039/c7cp00695k ◽

2017 ◽

Vol 19 (16) ◽

pp. 10644-10650 ◽

Cited By ~ 20

Author(s):

Huabing Shu ◽

Yilong Tong ◽

Jiyuan Guo

Keyword(s):

Optical Properties ◽

Optical Absorption ◽

Electric Field ◽

Band Gap ◽

Absorption Spectra ◽

Optical Absorption Spectra ◽

Electric Field Effects ◽

Electronic And Optical Properties ◽

Vertical Electric Field ◽

Variable Band Gap

The variable band-gap of the Si/As heterostructure (left) and optical absorption spectra for AA-stacking under a vertical electric field (right).

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Influence of Air Annealing and Gamma Ray Irradiation on the Optical Properties of Cl16FePc Thin Films

E-Journal of Chemistry ◽

10.1155/2012/726415 ◽

2012 ◽

Vol 9 (4) ◽

pp. 2439-2445 ◽

Cited By ~ 3

Author(s):

Raji Koshy ◽

C. S. Menon

Keyword(s):

Thin Films ◽

Optical Properties ◽

Absorption Spectrum ◽

Optical Absorption ◽

Band Gap ◽

Gamma Ray ◽

Optical Transition ◽

High Electron ◽

Glass Substrates ◽

Optical Dielectric Constant

Metal phthalocyanines are one of the most promising candidates to be used in the fabrication of such devices. Among various phthalocyanines, Iron Hexadecachloro Phthalocyanine (Cl16FePc) has received less attention. Basic characteristics of Cl16FePc are not reported in literature. Hexadecacholoro phthalocyanines have attracted interest as possible n-type organic semiconductor with high electron mobility and good stability characteristics. In the present work we investigate the optical band gap of the Cl16FePc thin films from the optical absorption spectrum as a function of air annealing temperatures and their suitability for the fabrication of molecular electronic devices. Some optical properties of the samples were studied as a function of γ-radiation doses also. Optical transition is found to be of direct type and optical band gaps are determined by analyzing the absorption spectrum. Vacuum sublimed thin films of Iron hexadecachloro phthalocyanine were prepared at room temperature onto glass substrates at a base pressure of 10-5Torr on precleaned glass substrates using Hind Hivac 12A4 coating plant. The optical energy band gap Eg were calculated. The mechanism of optical absorption follow the rule of direct transition. In the present paper we also report refractive index, real and imaginary parts of optical dielectric constant etc. from the reflectance measurements.

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Electronic and optical properties of ternary alloys ZnxCd1−xS, ZnxCd1−xSe, ZnSxSe1−x, MgxZn1−xSe

Materials Science-Poland ◽

10.1515/msp-2017-0005 ◽

2017 ◽

Vol 35 (1) ◽

pp. 32-39

Author(s):

K. Benchikh ◽

H. Abid ◽

M. Benchehima

Keyword(s):

Optical Properties ◽

Detailed Comparison ◽

Ternary Alloys ◽

Band Structures ◽

Virtual Crystal Approximation ◽

Electronic And Optical Properties ◽

Empirical Pseudopotential Method ◽

Direct Band ◽

Alloy Concentration ◽

Good Agreement

AbstractThe empirical pseudopotential method (EPM) within the virtual crystal approximation (VCA) is used to calculate the electronic and optical properties of ternary alloys ZnxCd1−xS, ZnxCd1−xSe, ZnSxSe1−x and MgxZn1−xSe. The alloy band structures and energy gaps are calculated using VCA which incorporates the compositional disorder as an effective potential. The calculated band structures for the ZnxCd1−xS, ZnxCd1−xSe and ZnSxSe1−x alloys show a direct band gap in the whole range of the concentration except for the MgxZn1−xSe alloy which presents a crossover from the direct gap to the indirect one.Also the dependence of the refractive index on the concentration is calculated for each ternary alloy. This parameter is found to depend nonlinearly on the alloy concentration. A detailed comparison of our results with experimental data and works of other authors has led to a good agreement.

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Effects of annealing and cobalt implantation on the optical properties of βFeSi2

MRS Proceedings ◽

10.1557/proc-320-173 ◽

1993 ◽

Vol 320 ◽

Cited By ~ 2

Author(s):

M S Finney ◽

Z Yang ◽

M A Harry ◽

K J Reeson ◽

K P Homewood ◽

...

Keyword(s):

Optical Properties ◽

Optical Absorption ◽

Band Gap ◽

Small Dose ◽

Ion Beam ◽

Hydrogen Plasma ◽

High Dose ◽

Additional Band ◽

A Value ◽

Fe Implantation

ABSTRACTIn this paper optical absorption and photoluminescence (PL) techniques are used to study the optical properties of βFeSi2 layers fabricated by Ion Beam Synthesis (IBS). The way in which the band-gap varies when a small dose of Co is added before Fe implantation is also investigated. Our results indicate that the band-gap for βFeSi2 is direct with a value of 0.87eV. When a sufficiently high dose (1 ×10 16cm2) of Co is implanted prior to Fe we see the appearance of an additional band-gap after annealing at 1173K which we attribute to the formation of a ternary CoxFeySiz phase. We also show that by placing the sample in a hydrogen plasma it is possible to raise the temperature at which PL occurs in βFeSi2 to σ 200K.

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Effects of annealing and cobalt implantation on the optical properties of βFeSi2.

MRS Proceedings ◽

10.1557/proc-316-433 ◽

1993 ◽

Vol 316 ◽

Cited By ~ 6

Author(s):

M S Finney ◽

Z Yang ◽

M A Harry ◽

K J Reeson ◽

K P Homewood ◽

...

Keyword(s):

Optical Properties ◽

Optical Absorption ◽

Band Gap ◽

Small Dose ◽

Ion Beam ◽

Hydrogen Plasma ◽

High Dose ◽

Additional Band ◽

A Value ◽

Fe Implantation

ABSTRACTIn this paper optical absorption and photoluminescence (PL) techniques are used to study the optical properties of βFeSi2 layers fabricated by Ion Beam Synthesis (IBS). The way in which the band-gap varies when a small dose of Co is added before Fe implantation is also investigated. Our results indicate that the band-gap for βFeSi2 is direct with a value of O.87eV. When a sufficiently high dose (1×1016cm-2) of Co is implanted prior to Fe we see the appearance of an additional band-gap after annealing at 1173K which we attribute to the formation of a ternary CoxFeySiz, phase. We also show that by placing the sample in a hydrogen plasma it is possible to raise the temperature at which PL occurs in βFeSi2 to ~ 200K.

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Optical Properties of Colloidal CdSe/ZnS core/shell Nanocrystals Embedded in a UV Curable Resin

MRS Proceedings ◽

10.1557/proc-0959-m06-04 ◽

2006 ◽

Vol 959 ◽

Author(s):

Abhishek Joshi ◽

Edwin Davis ◽

Kaushik Narsingi ◽

Omar Manasreh ◽

B. D. Weaver

Keyword(s):

Optical Properties ◽

Optical Absorption ◽

Band Gap ◽

Absorption Spectra ◽

Energy Band ◽

Core Shell ◽

Optical Absorption Spectra ◽

Energy Band Gap ◽

Uv Curable ◽

Uv Curable Resin

ABSTRACTOptical absorption and photoluminescence techniques were used to investigate the band gap of colloidal CdSe/ZnS core/shell nanocrystals matrixed in a UV curable resin. The band gap was measured for several nanocrystals with size ranging between 1.9 and 4.0 nm. The band gap (Eg) was determined from the first exciton peaks observed in the optical absorption spectra. Both Debye and Einstein temperatures were estimated from fitting the energy band gap vs. temperature using two different empirical expressions.

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Effect of Copper Concentration on the Optical Properties of Cu2Zn0.8Cd0.2SnS4 Pentrary Alloy Nanostructures

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1115.373 ◽

2015 ◽

Vol 1115 ◽

pp. 373-377 ◽

Cited By ~ 2

Author(s):

A.S. Ibraheam ◽

Y. Al-Douri ◽

U. Hashim

Keyword(s):

Optical Properties ◽

Optical Absorption ◽

Band Gap ◽

Glass Substrate ◽

Copper Concentration ◽

Sol Gel ◽

Gel Method ◽

Cu Content ◽

Alloy Nanostructures ◽

Effect Of Copper

Cu2Zn0.2Cd0.8SnS4pentrary alloy nanostructures deposited at different molarity copper 0.3, 0. 5, 0. 7 and 0.9 M were grown by sol-gel method on glass substrate. The optical absorption indicates that the band gap of Cu2Zn0.2Cd0.8SnS4nanostructures decreases linearly from 1.80 eV (0.3M 0) to 1.60 eV (0.9M). The transmittance value is in the range 63-49% depending on the Cu content.

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