Enhanced optical and thermoelectric properties of ZnO by tin and fluorine codoping: First-principles DFT calculations

Ab initio density functional calculations of the structural, optoelectronic, thermoelectric and thermodynamic properties of ZnO codoped with tin and fluorine with possible application as Transparent Conductive Oxides (TCO’s), are reported in this work. This study shows that incorporation of Sn and F into the ZnO matrix converts it to a degenerate semiconductor. The calculated optical absorption coefficients show that the four compounds ZnO, Sn:ZnO, F:ZnO and Sn:F:ZnO have transparent properties in the visible range. At 900[Formula: see text]K, the Seebeck coefficient of Sn:F:ZnO is greatly improved with respect to the undoped ZnO. A maximum electrical conductivity value of [Formula: see text]S cm[Formula: see text]s[Formula: see text] is predicted for Sn-doped ZnO. ZT increases with temperature to a maximum value of 0.13 at 900[Formula: see text]K for tin and fluorine codoped ZnO.

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Cu-Doped ZnO Electronic Structure and Optical Properties Studied by First-Principles Calculations and Experiments

Materials ◽

10.3390/ma12010196 ◽

2019 ◽

Vol 12 (1) ◽

pp. 196 ◽

Cited By ~ 22

Author(s):

Zhanhong Ma ◽

Fengzhang Ren ◽

Xiaoli Ming ◽

Yongqiang Long ◽

Alex A. Volinsky

Keyword(s):

Optical Absorption ◽

Conduction Band ◽

First Principles ◽

Density Functional ◽

Geometric Optimization ◽

Experimental Results ◽

Impurity Level ◽

Original Structure ◽

Generalized Gradient ◽

Doped Zno

The band structure, the density of states and optical absorption properties of Cu-doped ZnO were studied by the first-principles generalized gradient approximation plane-wave pseudopotential method based on density functional theory. For the Zn1-xCuxO (x = 0, x = 0.0278, x = 0.0417) original structure, geometric optimization and energy calculations were performed and compared with experimental results. With increasing Cu concentration, the band gap of the Zn1-xCuxO decreased due to the shift of the conduction band. Since the impurity level was introduced after Cu doping, the conduction band was moved downwards. Additionally, it was shown that the insertion of a Cu atom leads to a red shift of the optical absorption edge, which was consistent with the experimental results.

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First-Principles Evaluation of the Potential of Borophene as a Monolayer Transparent Conductor

10.26434/chemrxiv.5439880 ◽

2017 ◽

Author(s):

Lyudmyla Adamska ◽

Sridhar Sadasivam ◽

Jonathan J. Foley ◽

Pierre Darancet ◽

Sahar Sharifzadeh

Keyword(s):

First Principles ◽

Density Functional ◽

State Of The Art ◽

Transparent Electrode ◽

Visible Range ◽

Two Dimensional ◽

Transparent Conductor ◽

Many Body ◽

Functional Theory ◽

Many Body Perturbation Theory

Two-dimensional boron is promising as a tunable monolayer metal for nano-optoelectronics. We study the optoelectronic properties of two likely allotropes of two-dimensional boron using first-principles density functional theory and many-body perturbation theory. We find that both systems are anisotropic metals, with strong energy- and thickness-dependent optical transparency and a weak (<1%) absorbance in the visible range. Additionally, using state-of-the-art methods for the description of the electron-phonon and electron-electron interactions, we show that the electrical conductivity is limited by electron-phonon interactions. Our results indicate that both structures are suitable as a transparent electrode.

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Comparative Study on Electronic Structure and Optical Properties of α-Fe2O3, Ag/α-Fe2O3 and S/α-Fe2O3

Metals ◽

10.3390/met11030424 ◽

2021 ◽

Vol 11 (3) ◽

pp. 424

Author(s):

Cuihua Zhao ◽

Baishi Li ◽

Xi Zhou ◽

Jianhua Chen ◽

Hongqun Tang

Keyword(s):

Optical Properties ◽

Optical Absorption ◽

Electronic Structures ◽

Density Functional ◽

Peak Strength ◽

Visible Range ◽

High Symmetry ◽

Functional Theory ◽

Optical Absorption Peak ◽

Calculation Results

The electronic structures and optical properties of pure, Ag-doped and S-doped α-Fe2O3 were studied using density functional theory (DFT). The calculation results show that the structure of α-Fe2O3 crystal changes after Ag and S doping, which leads to the different points of the high symmetry of Ag-doped and S-doped α-Fe2O3 with that of pure α-Fe2O3 in the energy band, as well as different Brillouin paths. In addition, the band gap of α-Fe2O3 becomes smaller after Ag and S doping, and the optical absorption peak shifts slightly toward the short wavelength, with the increased peak strength of S/α-Fe2O3 and the decreased peak strength of Ag/α-Fe2O3. However, the optical absorption in the visible range is enhanced after Ag and S doping compared with that of pure α-Fe2O3 when the wavelength is greater than 380 nm, and the optical absorption of S-doped α-Fe2O3 is stronger than that of Ag-doped α-Fe2O3.

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Structural, elastic and thermodynamic properties of A15-type compounds V3X (X = Ir, Pt and Au) from first-principles calculations

Modern Physics Letters B ◽

10.1142/s0217984916504145 ◽

2016 ◽

Vol 30 (35) ◽

pp. 1650414 ◽

Cited By ~ 6

Author(s):

Mingliang Wang ◽

Zhe Chen ◽

Dong Chen ◽

Cunjuan Xia ◽

Yi Wu

Keyword(s):

Thermodynamic Properties ◽

Debye Temperature ◽

First Principles ◽

Density Functional ◽

Coefficient Of Thermal Expansion ◽

Local Density ◽

Debye Model ◽

First Principles Calculations ◽

Generalized Gradient ◽

Experimental Values

The structural, elastic and thermodynamic properties of the A15 structure V3Ir, V3Pt and V3Au were studied using first-principles calculations based on the density functional theory (DFT) within generalized gradient approximation (GGA) and local density approximation (LDA) methods. The results have shown that both GGA and LDA methods can process the structural optimization in good agreement with the available experimental parameters in the compounds. Furthermore, the elastic properties and Debye temperatures estimated by LDA method are typically larger than the GGA methods. However, the GGA methods can make better prediction with the experimental values of Debye temperature in V3Ir, V3Pt and V3Au, signifying the precision of the calculating work. Based on the E–V data derived from the GGA method, the variations of the Debye temperature, coefficient of thermal expansion and heat capacity under pressure ranging from 0 GPa to 50 GPa and at temperature ranging from 0 K to 1500 K were obtained and analyzed for all compounds using the quasi-harmonic Debye model.

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Strain Conditions for the Inverse Heusler Type Fully Compensated Spin-Gapless Semiconductor Ti2MnAl: A First-Principles Study

Materials ◽

10.3390/ma11112091 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2091 ◽

Cited By ~ 13

Author(s):

Tie Yang ◽

Liyu Hao ◽

Rabah Khenata ◽

Xiaotian Wang

Keyword(s):

Thermodynamic Properties ◽

First Principles ◽

Density Functional ◽

Theoretical Study ◽

Debye Model ◽

Pressure Effects ◽

First Principles Calculation ◽

Strain Condition ◽

Functional Theory ◽

Future Work

In this work, we systematically studied the structural, electronic, magnetic, mechanical and thermodynamic properties of the fully compensated spin-gapless inverse Heusler Ti2MnAl compound under pressure strain condition by applying the first-principles calculation based on density functional theory and the quasi-harmonic Debye model. The obtained structural, electronic and magnetic behaviors without pressure are well consistent with previous studies. It is found that the spin-gapless characteristic is destroyed at 20 GPa and then restored with further increase in pressure. While, the fully compensated ferromagnetism shows a better resistance against the pressure up to 30 GPa and then becomes to non-magnetism at higher pressure. Tetragonal distortion has also been investigated and it is found the spin-gapless property is only destroyed when c/a is less than 1 at 95% volume. Three independent elastic constants and various moduli have been calculated and they all show increasing tendency with pressure increase. Additionally, the pressure effects on the thermodynamic properties under different temperature have been studied, including the normalized volume, thermal expansion coefficient, heat capacity at constant volume, Grüneisen constant and Debye temperature. Overall, this theoretical study presents a detailed analysis of the physical properties’ variation under strain condition from different aspects on Ti2MnAl and, thus, can provide a helpful reference for the future work and even inspire some new studies and lead to some insight on the application of this material.

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Thermodynamic Properties of CaSiO3 Perovskite at High Pressure and High Temperature

Zeitschrift für Naturforschung A ◽

10.1515/zna-2009-5-615 ◽

2009 ◽

Vol 64 (5-6) ◽

pp. 399-404 ◽

Cited By ~ 1

Author(s):

Zi-Jiang Liu ◽

Xiao-Ming Tan ◽

Yuan Guo ◽

Xiao-Ping Zheng ◽

Wen-Zhao Wu

Keyword(s):

Thermodynamic Properties ◽

First Principles ◽

Density Functional ◽

High Pressures ◽

Local Density ◽

Harmonic Approximation ◽

Debye Model ◽

Functional Theory ◽

Casio3 Perovskite ◽

First Time

The thermodynamic properties of tetragonal CaSiO3 perovskite are predicted at high pressures and temperatures using the Debye model for the first time. This model combines the ab initio calculations within local density approximation using pseudopotentials and a plane wave basis in the framework of density functional theory, and it takes into account the phononic effects within the quasi-harmonic approximation. It is found that the calculated equation of state is in excellent agreement with the observed values at ambient condition. Based on the first-principles study and the Debye model, the thermal properties including the Debye temperature, the heat capacity, the thermal expansion and the entropy are obtained in the whole pressure range from 0 to 150 GPa and temperature range from 0 to 2000 K.

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First-principles study of calcium-based sulfur fixers and their products

Thermal Science ◽

10.2298/tsci210824350c ◽

2021 ◽

pp. 350-350

Author(s):

Guoyan Chen ◽

Jianing Chen ◽

Anchao Zhang ◽

Haoxin Deng ◽

Yanyang Mei ◽

...

Keyword(s):

Calcium Carbonate ◽

Power Plant ◽

Thermodynamic Properties ◽

Calcium Oxide ◽

First Principles ◽

Calcium Sulfate ◽

Density Functional ◽

Stable State ◽

Generalized Gradient ◽

Calcium Sulphoaluminate

Calcium-based sulfur-fixing agent, as the main sulfur-fixing product, is widely used in power plant boiler systems. In order to further study the thermodynamic properties and reaction characteristics of calcium-based sulfur fixing agent and its products, the method of combining power plant experiment with theory was used. The electronic structure, thermodynamic properties and density of states of quicklime, limestone, calcium sulfate and calcium sulphoaluminate have been calculated based on the first-principles ultra-soft pseudopotential plane wave method of density functional theory. The generalized gradient approximation algorithm isused to optimize the structure of various minerals to achieve the most stable state. The results show that the enthalpy, entropy, specific heat capacity at constant pressure and Gibbs free energy of calcium sulfonate vary greatly from 25K to 1000K, while the change of calcium oxide is small, and that of calcium carbonate and calcium sulfate are between them. It shows that calcium sulphoaluminate has strong stability and more energy is needed to destroy the molecular structure of calcium sulphoaluminate. Calcium oxide is the most unstable and requires less energy to react; Calcium carbonate and calcium sulfate are in between. The variation range of calcium sulfate is greater than that of calcium carbonate, indicating that the stability of calcium sulfate is higher than that of calcium carbonate. The experimental results show that the desulfurization efficiency of generating calcium sulphoaluminate is much higher than that of only generating calcium sulfate, indicating that calcium sulphoaluminate is very stable, which is consistent with the calculated results.

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New Zirconium Diboride Polymorphs—First-Principles Calculations

Materials ◽

10.3390/ma13133022 ◽

2020 ◽

Vol 13 (13) ◽

pp. 3022 ◽

Cited By ~ 1

Author(s):

Marcin Maździarz ◽

Tomasz Mościcki

Keyword(s):

Thermodynamic Properties ◽

First Principles ◽

Density Functional ◽

Formation Enthalpy ◽

Density Functional Theory Calculations ◽

Zirconium Diboride ◽

Point Of View ◽

Phonon Modes ◽

Functional Theory ◽

Space Group

Two new hypothetical zirconium diboride (ZrB 2 ) polymorphs: (hP6-P6 3 /mmc-space group, no. 194) and (oP6-Pmmn-space group, no. 59), were thoroughly studied under the first-principles density functional theory calculations from the structural, mechanical and thermodynamic properties point of view. The proposed phases are thermodynamically stable (negative formation enthalpy). Studies of mechanical properties indicate that new polymorphs are less hard than the known phase (hP3-P6/mmm-space group, no. 191) and are not brittle. Analysis of phonon band structure and density of states (DOS) also show that the phonon modes have positive frequencies everywhere and the new ZrB 2 phases are not only mechanically but also dynamically stable. The estimated acoustic Debye temperature, Θ D , for the two new proposed ZrB 2 phases is about 760 K. The thermodynamic properties such as internal energy, free energy, entropy and constant-volume specific heat are also presented.

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First-Principles Study on Co-Doped ZnO with Oxygen Vacancy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.154-155.124 ◽

2010 ◽

Vol 154-155 ◽

pp. 124-129

Author(s):

Zhen Zhen Weng ◽

Zhi Gao Huang ◽

Wen Xiong Lin

Keyword(s):

Oxygen Vacancy ◽

First Principles ◽

Density Functional ◽

Exchange Interactions ◽

First Principles Calculations ◽

Functional Theory ◽

Ferromagnetic Exchange ◽

Ferromagnetic Ground State ◽

Doped Zno ◽

Co Doped

The interatomic exchange interactions and the electronic structure of Co-doped ZnO with and without oxygen vacancy have been investigated by the first-principles calculations based on density functional theory. It is found that the oxygen vacancy can strengthen the ferromagnetic exchange interaction between Co atoms and might be available for carrier mediation. The oxygen vacancy near to the Co atoms is more favorable for the ferromagnetic ground state.

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THERMODYNAMIC PROPERTIES OF MgSiO3 POST-PEROVSKITE

Modern Physics Letters B ◽

10.1142/s0217984910022391 ◽

2010 ◽

Vol 24 (03) ◽

pp. 315-324

Author(s):

ZI-JIANG LIU ◽

XIAO-WEI SUN ◽

CAI-RONG ZHANG ◽

LI-NA TIAN ◽

YUAN GUO

Keyword(s):

Thermodynamic Properties ◽

First Principles ◽

Density Functional ◽

High Pressures ◽

Local Density ◽

Harmonic Approximation ◽

Debye Model ◽

Functional Theory ◽

High Pressures And Temperatures ◽

First Time

The thermodynamic properties of MgSiO 3 post-perovskite are predicted at high pressures and temperatures using the Debye model for the first time. This model combines with ab initio calculations within local density approximation using pseudopotentials and a plane wave basis in the framework of density functional theory, and it takes into account the phononic effects within the quasi-harmonic approximation. It is found that the calculated equation of state of MgSiO 3 post-perovskite is in excellent agreement with the latest observed values. Based on the first-principles study and the Debye model, the thermal properties including the Debye temperature, the heat capacity, the thermal expansion, and the entropy are obtained in the whole pressure range from 0 to 150 GPa and temperature range from 0 to 2000 K.

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