scholarly journals First-Principles Study on the Stabilities, Electronic and Optical Properties of GexSn1-xSe Alloys

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 876 ◽  
Author(s):  
Qi Qian ◽  
Lei Peng ◽  
Yu Cui ◽  
Liping Sun ◽  
Jinyan Du ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Band Gap ◽  
Electronic Properties ◽  
First Principles ◽  
Future Application ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
Direct Bandgap ◽  
The Future

We systematically study, by using first-principles calculations, stabilities, electronic properties, and optical properties of GexSn1-xSe alloy made of SnSe and GeSe monolayers with different Ge concentrations x = 0.0, 0.25, 0.5, 0.75, and 1.0. Our results show that the critical solubility temperature of the alloy is around 580 K. With the increase of Ge concentration, band gap of the alloy increases nonlinearly and ranges from 0.92 to 1.13 eV at the PBE level and 1.39 to 1.59 eV at the HSE06 level. When the Ge concentration x is more than 0.5, the alloy changes into a direct bandgap semiconductor; the band gap ranges from 1.06 to 1.13 eV at the PBE level and 1.50 to 1.59 eV at the HSE06 level, which falls within the range of the optimum band gap for solar cells. Further optical calculations verify that, through alloying, the optical properties can be improved by subtle controlling the compositions. Since GexSn1-xSe alloys with different compositions have been successfully fabricated in experiments, we hope these insights will contribute to the future application in optoelectronics.

First Principles Investigation on the Structural, Electronic and Optical Properties of Amorphous Silica Glass

2017 ◽  
Vol 268 ◽  
pp. 92-96
Author(s):  
R.M. Nor ◽  
S.N.M. Halim ◽  
Mohamad Fariz Mohamad Taib ◽  
M. Kamil Abd-Rahman
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Electronic Properties ◽  
Amorphous Silica ◽  
First Principles ◽  
Glass Structure ◽  
Small Sample ◽  
First Principles Calculation ◽  
Electronic And Optical Properties ◽  
Amorphous Quartz

The structural, electronic, and optical properties of an amorphous SiO2 (a-SiO2) model is investigated by using first-principles calculation. Most research works used beta-cristobalite glass structure as a reference to amorphous silica structure. However, only the electronic properties were been presented without any link towards the optical properties. Here, we demonstrate simultaneous electronic and optical properties, which closely matched to a-SiO2 properties by generating small sample of amorphous quartz glass. Using the Rietveld refinement, amorphous silica structure was generated and optimized using density functional theory in CASTEP computer code. A thorough analysis of the amorphous quartz structure obtained from different thermal treatment was carried out. The structure of amorphous silica was validated with previous theoretical and experimental works. It is shown that small sample of amorphous silica have similar structural, electronic and optical properties with a larger sample. The calculated optical and electronic properties from the a-SiO2 glass match closely to previous theoretical and experimental data from others. The a-SiO2 band gap of 5.853 eV is found to be smaller than the experimental value of ~9 eV. This is due to the underestimation and assumption made in DFT. However, the band gap value is in good agreement with the other theoretical works. Apart from the absorption edge at around 6.5 eV, the refractive index is 1.5 at 0eV. Therefore, this atomic structure can served as a reference model for future research works on amorphous structures.

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].

scholarly journals Effects of the number of layers on the vibrational, electronic and optical properties of alpha lead oxide

2019 ◽  
Vol 21 (7) ◽  
pp. 3868-3876 ◽  
Author(s):  
Ali Bakhtatou ◽  
Fatih Ersan
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Ultrathin Films ◽  
First Principles ◽  
Lead Oxide ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
Number Of Layers

We have investigated the effects of the number of layers on the structure, vibrational, electronic and optical properties of α-PbO using first principles calculations. Our calculations have indicated that ultrathin films of α-PbO (such as 3 nm thickness) could be excellent candidates for solar cells.

Electronic and optical properties of Janus Monolayers MoXB2(X=S,Se): First-principles prediction

2021 ◽  
Author(s):  
Qingwen Lan ◽  
Changpeng Chen ◽  
Tian Qin
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
First Principles ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
Direct Band Gap ◽  
Direct Band ◽  
Indirect Band Gap ◽  
The Stability ◽  
Optical Calculation

By means of comprehensive first-principles calculations, we studied the geometric structure, the stability and electronic properties of the new two-dimensional(2D) Janus MoXB2(X=S, Se) monolayers. Our calculations demonstrated that the predicted Janus MoXB2 monolayers are all stable semiconductors with direct band gap. In this paper, we focus on impacts upon the electronic and optical properties of the MoXB2 monolayers under the different biaxial strains. With the compressive stress increases, the MoXB2 monolayers would become indirect band gap semiconductors, and then behave as semimetal. While under tensile strain, MoXB2 still maintain direct band gap. In addition, the optical calculation shows that biaxial strain leads to blue shifts in the optical absorption and reflectivity. The result indicates that MoXB2 may be promised nano candidate materials in optoelectronic devices.

scholarly journals $ZrO_{2}$ electronic properties

2021 ◽  
Author(s):  
Phillip Barry
Keyword(s):  
Optical Properties ◽  
Electronic Properties ◽  
First Principles ◽  
Zirconium Dioxide ◽  
Noble Metals ◽  
Industrial Applications ◽  
First Principles Calculations ◽  
Electronic And Optical Properties

The improvement of electronic and optical properties of the Zirconium dioxide $ZrO_{2}$ is very significance for the industrial applications. Here, we apply the first-principles calculations to study the influence of noble metals on the electronic and optical properties of the monoclinic $ZrO_{2}$

A first-principles study on the electronic and optical properties of a type-II C2N/g-ZnO van der Waals heterostructure

2021 ◽  
Vol 23 (6) ◽  
pp. 3963-3973
Author(s):  
Jianxun Song ◽  
Hua Zheng ◽  
Minxia Liu ◽  
Geng Zhang ◽  
Dongxiong Ling ◽  
...  
Keyword(s):  
Optical Properties ◽  
Dft Calculations ◽  
First Principles ◽  
Van Der Waals ◽  
Band Alignment ◽  
Type Ii ◽  
Electronic And Optical Properties ◽  
Direct Bandgap ◽  
Van Der Waals Heterostructure ◽  
Vdw Heterostructure

The structural, electronic and optical properties of a new vdW heterostructure, C2N/g-ZnO, with an intrinsic type-II band alignment and a direct bandgap of 0.89 eV at the Γ point are extensively studied by DFT calculations.

scholarly journals The electronic and optical properties of Au decorated(1 01¯4) dolomite surface: A first principles calculations

2021 ◽  
Vol 21 ◽  
pp. 103827
Author(s):  
Jianrong Wang ◽  
Weibin Zhang ◽  
Qingfeng Wu ◽  
Shufang Gao ◽  
Yuanyuan Jin ◽  
...  
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
First Principles Calculations ◽  
Electronic And Optical Properties

scholarly journals First-principles study on structural, electronic and optical properties of perovskite solid solutions KB1−xMgxI3 (B = Ge, Sn) toward water splitting photocatalysis

RSC Advances ◽  
2021 ◽  
Vol 11 (42) ◽  
pp. 26432-26443
Author(s):  
Chol-Hyok Ri ◽  
Yun-Sim Kim ◽  
Un-Gi Jong ◽  
Yun-Hyok Kye ◽  
Se-Hun Ryang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Water Splitting ◽  
Potassium Iodide ◽  
Solid Solutions ◽  
First Principles ◽  
Lead Free ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
First Principles Study

We propose lead-free potassium iodide perovskite solid solutions KBI3 with B-site mixing between Ge/Sn and Mg as potential candidates for photocatalysts based on systematic first-principles calculations.

scholarly journals Electronic and optical properties of vacancy ordered double perovskites A2BX6 (A = Rb, Cs; B = Sn, Pd, Pt; and X = Cl, Br, I): a first principles study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Faizan ◽  
K. C. Bhamu ◽  
Ghulam Murtaza ◽  
Xin He ◽  
Neeraj Kulhari ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
First Principles ◽  
Density Functional ◽  
Perovskite Solar Cells ◽  
Dielectric Constants ◽  
Maximum Efficiency ◽  
Exchange Potential ◽  
Double Perovskites ◽  
Electronic And Optical Properties

AbstractThe highly successful PBE functional and the modified Becke–Johnson exchange potential were used to calculate the structural, electronic, and optical properties of the vacancy-ordered double perovskites A2BX6 (A = Rb, Cs; B = Sn, Pd, Pt; X = Cl, Br, and I) using the density functional theory, a first principles approach. The convex hull approach was used to check the thermodynamic stability of the compounds. The calculated parameters (lattice constants, band gap, and bond lengths) are in tune with the available experimental and theoretical results. The compounds, Rb2PdBr6 and Cs2PtI6, exhibit band gaps within the optimal range of 0.9–1.6 eV, required for the single-junction photovoltaic applications. The photovoltaic efficiency of the studied materials was assessed using the spectroscopic-limited-maximum-efficiency (SLME) metric as well as the optical properties. The ideal band gap, high dielectric constants, and optimum light absorption of these perovskites make them suitable for high performance single and multi-junction perovskite solar cells.

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