An in-depth analysis of the optoelectronics, phonon, mechanical, thermodynamic and transport attributes of lead-free K ₂ TlInX ₆ (X= I, Br) double perovskites for green energies

In the renewable energy industries, halide double perovskite compounds have become revolutionary materials because of their higher power conversion ability and environmental friendliness. Therefore, in this paper, we have scrutinized the physical traits of halide double perovskites K 2 TlInX 6 (X[Formula: see text] I, Br) using a DFT-based code as Wien2K. The ground state parameters for K 2 TlInX 6 (X[Formula: see text] I, Br) are analyzed using the GGA functional, whereas the mBJ is employed to analyze the rest of the physical properties. The structural, dynamic and thermodynamic stability are ensured through optimization plots, phonon plots, negative formation energies and tolerance factor for K 2 TlInX 6 (X[Formula: see text] I, Br). The studied halides show complete mechanical stability. The elastic anisotropy is analyzed using the ELATE software. Indirect bandgap of 1.43 eV and 2.41 eV are revealed via electronic properties of K 2 TlInI 6 and K 2 TlInBr 6 . A comprehensive assessment of the optical attributes of K 2 TlInX 6 (X[Formula: see text] I, Br) is done via Kramer’s complex equations. Moreover, the transport attributes are evaluated using the BoltzTraP code. By analyzing K 2 TlInX 6 (X[Formula: see text] I, Br)’s structural, mechanical, electrical, optical and transport properties, it is concluded that these halides are feasible to be employed in thermoelectric and optoelectronic devices.