Unveiling the structural stability, optoelectronic and thermoelectric features of NaXI ₃ (X=Sr, Be) halide perovskite for optoelectronic and green energy technology

Halide Perovskite materials have become very popular recently as a potential safe and eco-friendly alternative to lead-based hybrid perovskites because of their outstanding structure, electrical properties and stability. The structural, optoelectronic and charge transport properties of the NaXI 3 ([Formula: see text], Be) perovskites are calculated using first-principles methods, specifically the density functional theory as implemented in the WIEN2K code. The structural stability was confirmed through calculations of the formation energy, tolerance factor and binding energy. The electronic properties were estimated by employing the PBE-GGA approximation. The electronic band gap of NaBeI 3 and NaSrI 3 has been found to be 1.77 and 1.51[Formula: see text]eV, respectively, by the PBE-GGA approximation. For better estimation of band gap, we have also utilized TB-mBJ potential which was 2.59[Formula: see text]eV for NaBeI 3 and 2.27[Formula: see text]eV for NaSrI 3 . PDOS results elaborates that the formation of V.B and C.B is due to I-5p, Be-2s and Na-3s energy states. Regarding the optical results NaBeI 3 absorbs 105–318[Formula: see text]nm and NaSrI 3 absorbs 111–410[Formula: see text]nm in ultraviolet spectrum which indicates that these compounds are suitable for optoelectronic and allied applications. The charge transport characteristics such as power factor, electrical conductivity, Seebeck coefficient and electronic thermal conductivity can be calculated by BoltzTrap code. The estimated result demonstrates that both studied compounds are favorable materials for high-temperature thermoelectric devices. It is expected that researchers and scientists will utilized these materials to manufacture devices based on optoelectronic and thermoelectric results for green applications.