Exploring the structural, optoelectronic, elastic, and thermoelectric properties of cubic ternary fluoro-perovskites sodium based NaMF₃ (M = Si and Ge) compounds for heterojunction solar cells applications

Abstract

In current research the structural, optoelectronic, elastic, and thermoelectric properties of NaMF3 (M = Si and Ge) ternary perovskites (Halide Perovskites) compounds using first-principle modeling are computed within the DFT framework. The obtained results of phonons dispersion curves and the tolerance factor is calculated for NaSiF3 and NaGeF3 and is found to be 1.001 and 1.004 respectively, which reveals that these compounds are structurally and thermodynamically stable in cubic phase. The elastic constants and other parameters demonstrates that these compounds are mechanically stable, hard to scratch, ductile, anisotropic and possesses resistance to plastic distortion. The band structure and density of states (DOS) demonstrate the semiconducting nature for the NaSiF3 and NaGeF3 compounds with direct band gap of 1.15 eV and 3.31 eV respectively from “R-R” symmetries points. The optical properties are investigated and it is observed that the selected compounds possess strong optical conduction and absorption coefficient and are transparent at low incident photons energy ranges and led us to the conclusion that for high frequency UV device these compounds possesses suitable applications. The thermoelectric properties indicate that both the materials possesses notable power factor and figure of merit (ZT), due to which its applications in solar cells can be deemed. To our knowledge, this is first NaMF3 (M= Si and Ge) theoretical computational systematic study of structural, optoelectronic, elastic, and thermoelectric properties which will experimentally validated. Our findings add comprehensive insight in predicting fabricating high performance hetero-junction solar cells.

First-principles study on the optoelectronic and mechanical properties of all-inorganic lead-free fluoride perovskites ABF3 (A = Na, K and B = Si, Ge)

“…We also confirmed that the HSE06 hybrid functional yielded remarkably larger band gaps compared to the PBE functional for the fluoride perovskites due to a upward shift of conduction bands and a downward shift of valence bands. Experimental and theoretical data are not yet available for these fluoride perovskites, except KGeF 3 (NaSiF 3 ), for which the band gap was calculated to be 2.00 (1.15) eV with the PBE (HSE06) functional 41,67 in accordance with our calculation of 1.97 (1.24) eV with the same XC functional (see Table 1). As far as believing the HSE06 calculations, the Si-based fluoride perovskites ASiF 3 (A = Na, K) were found to be suitable for visible light absorber applications because of their appropriate band gaps of 1.24 eV (A = Na) and 1.37 eV (A = K).…”

“…41 bThe band gap were calculated with HSE06 functional. 67 cOur previous first-principles work using Quantum ESPRESSO code. 68 dOur previous first-principles work using VASP code.…”

Investigation of the structural, electronic, mechanical, and optical properties of NaXCl3 (X = Be, Mg) using density functional theory

“…6,7 Among the properties exhibited by perovskite materials are thermoelectricity, dielectricity, superconductivity, ferroelectricity, optical properties, and various other distinctive characteristics. 8–10 A particular class of perovskites, recognized as chloroperovskites or metal halide perovskites, involve the replacement of the X-anion with a halogen element, commonly chlorine (Cl). Chloroperovskites, which are widely found in perovskite structures, are represented by the formula ABCl 3 , where “A” and “B” can represent alkali metals, alkaline earth metals, transition metals, and “Cl” represents chlorine.…”

Crystal structure, stability, and transport properties of Li2BeAl and Li2BeGa Heusler alloys: a DFT study

“…The structural, thermoelectric, half-metallic, optical, and thermoelectric properties of different classes of perovskites such as A 2 BCl 6 (A = Cs, K and B = Se, Sn, Ta, Te, Ti, W, Zr, Mn, Mo, Os, Pd, Pt, Re, Ru, Tc, W), 14 Cs 2 ABF 6 (AB = BiAu, AgIr, CuBi, GaAu, InAs, InAg, InAu, InSb and InBi), 15 Sr 2 EuReO 6, 16 Ba 3 B(Nb,Ta) 2 O 9 (B = Mg, Ca, Sr, Cd, Hg, Zn, Fe, Mn, Ni, and Co), 17 XZrO 3 (X = Ca, Sr, Ba), 18 SrMO 3 (M = Hf and Pt), 19 AgBeX 3 (X = F and Cl), 20 AGeF 3 (A = Ga and In), 21 LiRCl 3 (R = Be and Mg), 22 NaMF 3 (M = Si and Ge), 23 AlRF 3 (R = N, P), 24 and BWF 3 (W = S and Si) 25 were recently investigated by different researchers using DFT methods. These compounds were suggested to be good candidates for using in thermoelectric, spintronic, optical, energy storage, and optoelectronic applications.…”