Study of the structural, electronic, mechanical, electro-thermal and optical properties of double perovskite structures Cs₂SbAgX₆, (X = I, Br, or Cl)

Abstract

In the double perovskites structures, Cs2SbAgX6, X is I, Br, or Cl, the structural, electronic, thermodynamic, thermoelectric and optical, properties have been investigated by using the density functional theory (DFT) correction method. The XRD structural study exhibits that the double perovskite structures are stable in the cubic phase structures. Elastic parameters reveal all structures to be very hard and ductile in nature. The energy band profiles display indirect band-gap of semiconductor behavior for the structures Cs2SbAgX6; X is Cl or Br, while exhibiting metallic behavior of the structure Cs2SbAgI6. The thermoelectric transport properties were verified in the temperature range (5-1000) K, which includes electrical conductivity, thermal conductivity, Seebeck coefficients, and the figure of merit, ZT, for Cs2SbAgX6 structures. These structures exhibit high thermal conductivity with good Seebeck coefficients at room temperature. The semiconducting structure, Cs2SbAgBr6, has appropriate band gaps and best Seebeck coefficients; therefore, it has the best values of ZT reached 0.00016 at 1000K, which means the suitable structure for employment in thermoelectric and spintronic devices applications. The optical properties of these structures exhibit that the absorption effective region at the Visible-Ultraviolet region, therefore these materials are suitable in the applications of solar cells and optoelectronic devices.

Structural, electronic, optical, elastic, thermodynamic and thermal transport properties of Cs2AgInCl6 and Cs2AgSbCl6 double perovskite semiconductors using a first-principles study

“…The thermal conductivities exhibited by CAIC and CASC materials are approximately 0.075 and 0.25 W m À1 K À1 , respectively, when subjected to a temperature of 300 K. Moreover, it is important to note that the thermal conductivity values of CAIC and CASC exhibit an enhancement of about 0.41 and 0.5 W m À1 K À1 , respectively. 103,124 Our findings indicate a reduction in the specific heat capacity by a factor of five, as well as a reduction in the thermal conductivity by a factor of six for CAIC and a factor of two for CASC. The lattice thermal conductivity outcomes of CAIC exhibited an apparent resemblance between Cs 2 BiAgCl 6 (CABC) and Cs 2 BiAgBr 6 (CABB), both of which showed remarkably low values at 0.078 and 0.065 W m À1 K À1 , respectively.…”

Pressure induced electronic and optical responses of vacancy-ordered double perovskites Cs2BX6 (B = Zr, Pd, Sn; X = Cl, Br, I)

“…Another research on Cs 2 AgInBr 6 reported a bandgap of 1.125 eV and excellent absorption coefficient [19]. Cs 2 SbAgX 6 (X = Cl, Br, I) reveals excelling bandgap and carrier mobilities [20]. Recent research also extends to dope the B site tetravalent metal cation in search of potential material for device fabrication: Cs 2 BX 6 : Ga 2 PdX 6 (X = Cl, Br, and I) [21], Cs 2 PtI 2 [22], Cs 2 PdBr 6 [23], etc.…”