Optical study of cubic, and orthorhombic structures of XCaCl 3 (X = K, Rb) compounds: Comparative Ab initio calculations

Larbi, Abderrahim Hadj; Hiadsi, S.; Hadjab, Moufdi; Saeed, Muhammad

doi:10.1016/j.ijleo.2018.03.128

Cited by 17 publications

(10 citation statements)

References 25 publications

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“…The values found for TlSrF 3 and TlZnF 3 are 4.78 Å and 4.20 Å respectively as calculated through GGA functional and are listed in table 1. The lattice constant of TlZnF 3 and TlSrF 3 are found to be in close agreement with values 4.19 Å [34] and (4.72 Å) [35] and found through other theoretical studies. The values of formation energy obtained for TlSrF 3 is −1.02 eV while that of TlZnF 3 is −1.95 eV, as shown in table 1.…”

Section: Resultssupporting

confidence: 89%

“…Structural properties TlSrF 3 and TlZnF 3 are perovskites with cubic crystal structures that belong to the space group Pm3m (# 221). Atomic positions in the elementary cell for Tl, X and F are (0, 0, 0), (0.5, 0.5, 0.5), and (0.5, 0, 0.5), respectively [34,35]. The optimized volumes of unit cells were obtained corresponding to total energy minima through selfconsistent force (SCF) calculation and by fitting the data using Birch Murnaghan equation [36,37] of state as shown in figure 1.…”

Section: Resultsmentioning

confidence: 99%

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A first-principles study of electronic, optical and thermoelectric properties of TlXF₃ (X: Zn, Sr) perovskite crystal structure

et al. 2023

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This study communicates the structural, electronic, optical, and thermoelectric properties of a perovskite TlXF3 (X: Zn, Sr) crystal structure using first-principles calculations. Both compounds were found structurally as well as thermodynamically stable in cubic phase. The bandgaps of both compounds belong to insulating region. The TlSrF3 exhibits direct bandgap of 4.37 eV at X symmetry point while TlZnF3 possess indirect bandgap of 3.95 eV (M-X). Using HSE functional, the calculated electronic bandgaps of TlSrF3 and TlZnF3 are 5.74 eV(X-X) and 5.36 eV (M-X), respectively. The analysis of electronic states in band structur shows that for TlSrF3, the top of valence band is composed of the F-p states whereas the states in lower potion of conduction band are impacted by the significant contribution of Tl-p orbital states. In case of TlZnF3, the states near the valence band maxima and conduction band minima are coming mainly form Tl atom. The dependence of thermoelectric properties such as electrical conductivity, Seebeck coefficient, Power factor, electronic thermal conductivity (κ) and Figure-of-merit (ZT) as a function of carrier concertation and temperature are investigated. The optical properties were also studied to understand the response of TlXF3 to incident photons of energies upto 14 eV. We conclude that the TlXF3 are promising candidates for electronic, thermoelectric and optoelectronic devices.

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Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

A first-principles study of electronic, optical and thermoelectric properties of TlXF₃ (X: Zn, Sr) perovskite crystal structure

et al. 2023

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“…A number of compounds with cubic perovskite structure showed promising results in optoelectronic technology [15][16][17]. Especially, calcium (Ca)-based non-toxic alkali halide perovskites ACaX 3 (A = K, Rb, Cs and X = Cl, F) and CsCaBr 3 exhibited promising behavior at ambient pressure [18][19][20][21][22][23][24][25][26][27]. However, some of these compounds may face some limitations to be used in device applications due to their wide band gap nature.…”

Section: Introductionmentioning

confidence: 99%

Red shift of lead-free halide perovskite RbCaCl₃ under pressure for enhancing optoelectronic performance

Saiduzzaman¹,

Hossain²,

Asif³

et al. 2023

Phys. Scr.

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This study focuses on the exploration of pressure effects on the structural, electronic, optical, and mechanical properties of a cubic halide perovskite RbCaCl3 using density functional theory. The calculated values of lattice constant and unit cell volume at zero pressure are justified by the previous experimental and theoretical studies. As pressure is applied both the lattice constant and unit cell volume decrease steadily because of bond length reduction inside the material. The indirect band gap nature of the studied perovskite transforms into direct under applied pressure of 40 GPa and more. Moreover, the band gap value significantly reduces under pressure effect from ultraviolet to visible energy region. Though the bonding nature of both Rb−Cl and Ca−Cl is initially ionic, the induced pressure slightly reduces the ionicity of Rb−Cl and makes the Ca−Cl bond covalent. The optical absorption reveals a red shift in the visible energy region advantageous for using RbCaCl3 in solar cell applications. In addition, the overall optical analysis reveals that the pressure-induced compound is more suitable for optoelectronic device applications than that of zero pressure system. The external hydrostatic pressure significantly affects the mechanical properties of titled compound, making it more ductile and anisotropic.

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“…one Cs atom at the corner of the cube, one Ca atom at the body center of the cube, and three X atoms at the three adjacent faces of the cube. The atomic position for Cs, Ca and X are (0, 0, 0), (0.5, 0.5, 0.5), and (0.5, 0, 0.5) respectively [1,4]. The optimized lattice constant is calculated by finding total energies at various lattice constants through volume relaxation, then curve fitting is applied on these data using Birch Murnaghan equation [24,25] of state (see figure 2).…”

Section: Structural Propertiesmentioning

confidence: 99%

“…In the last few decades, the use of halide phosphors is increasing exponentially with time because of their desirable properties, e.g., thermal stability, fast decay, high light yield, and high energy resolution [1]. Phosphors are used in medical imaging, high energy physics experiments, colored LED coated with luminescent materials (phosphor), and material science, motivating researchers to find new phosphors with improved performance.…”

Section: Introductionmentioning

confidence: 99%

The effect of substitutional doping of Yb²⁺ on structural, electronic, and optical properties of CsCaX ₃ (X: Cl, Br, I) phosphors: a first-principles study

Khan

Rahman

Zhang

et al. 2021

J. Phys.: Condens. Matter

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Using first-principles calculations, the effects of Yb2+ substitutional doping on structural, electronic, and optical properties of a series of perovskite compounds CsCaX 3 (X: Cl, Br, I), have been investigated. We employed generalized gradient approximation (GGA) and HSE hybrid functional to study the electronic and optical properties. A series of pristine CsCaX 3 (X: Cl, Br, I) is characterized as a non-magnetic insulator with indirect bandgap perovskite materials. These phosphor materials are suitable candidates for doping with lanthanide series elements to tune their electronic bandgaps according to our requirements because of their wide bandgaps. The calculated electronic bandgaps of CsCaX 3 (X: Cl, Br, I) are 3.7 eV (GGA) and 4.5 eV (HSE) for CsCaI3, 4.5 eV (GGA) and 5.3 eV (HSE) for CsCaBr3, and 5.4 eV (GGA) and 6.4 eV (HSE) for CsCaCl3. According to formation energies, the Yb2+ doped at the Ca-site is thermodynamically more stable as compared to all possible atomic sites. The electronic band structures show that the Yb2+ doping induces defective states within the bandgaps of pristine CsCaX 3 (X: Cl, Br, I). As a result, the Yb2+ doped CsCaX 3 (X: Cl, Br, I) become the direct bandgap semiconductors. The defective states above the valence band maximum are produced due to the f-orbital of the Yb atom. The impurity states near the conduction band minimum are induced due to the major contribution of d-orbital of the Yb atom and the minor contribution of s-orbital of the Cs atom. The real and imaginary parts of the dielectric function, optical reflectivity, electron energy loss spectrum, extinction coefficient, and refractive index of pristine and Yb2+ doped CsCaX 3 (X: Cl, Br, I) were studied. The optical dispersion results of dielectric susceptibility closely match their relevant electronic structure and align with previously reported theoretical and experimental data. We conclude that the Yb2+ doped CsCaX 3 (X: Cl, Br, I) are appealing candidates for optoelectronic devices.

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Optical study of cubic, and orthorhombic structures of XCaCl 3 (X = K, Rb) compounds: Comparative Ab initio calculations

Cited by 17 publications

References 25 publications

A first-principles study of electronic, optical and thermoelectric properties of TlXF₃ (X: Zn, Sr) perovskite crystal structure

A first-principles study of electronic, optical and thermoelectric properties of TlXF₃ (X: Zn, Sr) perovskite crystal structure

Red shift of lead-free halide perovskite RbCaCl₃ under pressure for enhancing optoelectronic performance

The effect of substitutional doping of Yb²⁺ on structural, electronic, and optical properties of CsCaX ₃ (X: Cl, Br, I) phosphors: a first-principles study

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Optical study of cubic, and orthorhombic structures of XCaCl 3 (X = K, Rb) compounds: Comparative Ab initio calculations

Cited by 17 publications

References 25 publications

A first-principles study of electronic, optical and thermoelectric properties of TlXF3 (X: Zn, Sr) perovskite crystal structure

A first-principles study of electronic, optical and thermoelectric properties of TlXF3 (X: Zn, Sr) perovskite crystal structure

Red shift of lead-free halide perovskite RbCaCl3 under pressure for enhancing optoelectronic performance

The effect of substitutional doping of Yb2+ on structural, electronic, and optical properties of CsCaX 3 (X: Cl, Br, I) phosphors: a first-principles study

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Optical study of cubic, and orthorhombic structures of XCaCl 3 (X = K, Rb) compounds: Comparative Ab initio calculations

A first-principles study of electronic, optical and thermoelectric properties of TlXF₃ (X: Zn, Sr) perovskite crystal structure

A first-principles study of electronic, optical and thermoelectric properties of TlXF₃ (X: Zn, Sr) perovskite crystal structure

Red shift of lead-free halide perovskite RbCaCl₃ under pressure for enhancing optoelectronic performance

The effect of substitutional doping of Yb²⁺ on structural, electronic, and optical properties of CsCaX ₃ (X: Cl, Br, I) phosphors: a first-principles study