Tuning of band gap by anions (Cl, Br, I) of double perovskites Rb₂AgAsX₆ (Cl, Br, I) for solar cells and thermoelectric applications

Abstract

Owing to remarkable stability, environmental friendliness, and excellent performance, lead-free double perovskites (DPs) are emerging materials for use as energy harvesting systems and thermoelectric generators. Herein, the optical, electronic, and thermoelectric characteristics of Rb2AgAsX6 (X = Cl, Br, I) are studied by first principle approach. The thermodynamic stability is ensured through formation energy and structural stability by calculating the tolerance factor. The studied DPs band gaps are tuned from 2.21 eV to 1.50 eV, and 0.52 eV by replacing the anions (Cl to Br, and I). The absorption regions varies from infrared to visible wavelength ranges, signifying the importance of studied compounds for optoelectronics. The broad absorption band of Rb2AgAsI6 in the visible region is important for solar cells. Furthermore, thermoelectric performance is evaluated based on the power factor and figure of merit (ZT). From thermoelectric calculations, a lower lattice thermal conductivity was observed while, a larger Seebeck coefficient guarantees higher ZT, which are important parameters for thermoelectric applications.

Optoelectronic and thermoelectric properties of novel stable lead-free cubic double perovskites A2NaIO6 (A = Ca, Sr) for renewable energy applications

“…Besides thermodynamic and structural stability, the dynamic stability of a material is also required for device fabrication. 43 The dynamic stability of both DPs was evaluated through phonon dispersion spectroscopy as shown in Fig. 2.…”

Appealing perspectives of the structural, electronic, elastic and optical properties of LiRCl3 (R = Be and Mg) halide perovskites: a DFT study

“…All of the results are negative, demonstrating that the chloroperovskite compounds LiRCl 3 (R = Be and Mg) are stable structurally. 2,53,54…”

Control of spin on ferromagnetism and thermoelectric properties of Sr(V/Cr)2S4; emergent spintronic aspirant

“…In addition, the combination of thermoelectric characteristics makes it possible to see the net impact on electron spin and the significance of thermoelectric devices. [52], (1/Ωm) at 100 K to 11.9/10.2 ×10 5 (1/Ωm) at 600 K, respectively. This is because there are more carriers present at higher temperatures (see figure 8(a)).…”