scholarly journals Anisotropic optical properties of GeS investigated by optical absorption and photoreflectance

2020 ◽  
Vol 1 (6) ◽  
pp. 1886-1894
Author(s):  
Agata Tołłoczko ◽  
Robert Oliva ◽  
Tomasz Woźniak ◽  
Jan Kopaczek ◽  
Paweł Scharoch ◽  
...  
Keyword(s):  
Optical Properties ◽  
Optical Absorption ◽  
Band Gap ◽  
Fundamental Band ◽  
Comprehensive Study

We present a comprehensive study of bulk GeS optical properties and their anisotropy, by investigation of the fundamental band gap of the material and the energetically higher direct transitions.

Magneto-optical properties of theGaxIn1−xSesystem near the fundamental band gap

1984 ◽  
Vol 30 (4) ◽  
pp. 1957-1961 ◽  
Author(s):  
G. Saintonge ◽  
J. L. Brebner
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Fundamental Band

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

2016 ◽  
Vol 30 (10) ◽  
pp. 1650120 ◽  
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.

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

2019 ◽  
Vol 33 (22) ◽  
pp. 1950266 ◽  
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].

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

2017 ◽  
Vol 19 (16) ◽  
pp. 10644-10650 ◽  
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).

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

2012 ◽  
Vol 9 (4) ◽  
pp. 2439-2445 ◽  
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.

THE REALIZATION OF TERAHERTZ BAND-GAP FROM InAs/GaSb TYPE II SUPERLATTICES

2011 ◽  
Vol 25 (07) ◽  
pp. 1021-1028
Author(s):  
L. L. LI ◽  
H. M. DONG ◽  
W. XU ◽  
Y. L. SHI
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
High Temperatures ◽  
Heavy Hole ◽  
Type Ii ◽  
Fundamental Band ◽  
Typical Sample ◽  
Gasb Layer ◽  
Terahertz Band ◽  
Type Ii Superlattices

We demonstrate theoretically that terahertz (THz) fundamental band-gap between the electron mini-band in the InAs layer and the heavy-hole mini-band in the GaSb layer can be realized in InAs/GaSb -based type II superlattices (SLs). The THz band-gap can be tuned by varying the widths of the InAs/GaSb layers. The presence of such band-gap can result in a strong cut-off on optical absorption at THz frequencies. For typical sample structures, the THz cut-off of the optical absorption depends sensitively on temperature and a sharper cut-off can be observed at relatively high temperatures. This study is pertinent to the application of InAs/GaSb type II SLs as THz photodetectors.

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

2016 ◽  
Vol 4 (39) ◽  
pp. 9294-9302 ◽  
Author(s):  
Juan Du ◽  
Congxin Xia ◽  
Tianxing Wang ◽  
Wenqi Xiong ◽  
Jingbo Li
Keyword(s):  
Optical Properties ◽  
Optical Absorption ◽  
Band Gap ◽  
Group Iv ◽  
Band Structures ◽  
Alloy Concentration

The band gap and optical absorption can be tuned effectively by the alloy concentration x in the C2N1−xPx and C2N1−xAsx alloys.

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

1993 ◽  
Vol 320 ◽  
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.

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

1993 ◽  
Vol 316 ◽  
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.

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

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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