Summary
The vacancy‐ordered double perovskites are emerging candidates for solar cells and thermoelectric applications. Therefore, the A2ZrI6 (A = Ga, In, Tl) are systematically investigated for optical, electronics, and thermoelectric properties. The structural, and thermal stabilities are addressed by tolerance factor and formation energy. The energy band gaps ensure a direct band gap, which increases from 2.25 to 2.28 eV, and 2.37 eV by the substitution of Ga with In and Tl. The maximum absorption bands 477 to 335 nm, 471 to 400 nm, and 464 to 357 nm ensure the absorption in visible and ultraviolet regions for Ga2ZrI6, In2ZrI6 and Tl2ZrI6, respectively. Moreover, the thermoelectric characteristics are measured in the range of temperature (0 to 600 K) and chemical potential (−0.15 to 0.30 eV). The figure of merit has significant values at low and room temperatures which ensure the importance of studied materials for thermoelectric applications.