Lead-Free halide perovskites for optoelectronic application: Investigation of structural, optical, electric and dielectric behaviors

Lead-free all-inorganic perovskite single crystals (SCs) are currently the subject of a lot of research because of their enhanced material stability and lower biological toxicity. These advancements are essential for removing major obstacles to the real-world implementation of device applications. The lead-free hybrid organic-inorganic compound (CH3NH3)(2)MnCl4 was synthesized in this work at room temperature employing the slow evaporation solution growth approach. Investigating its structural, optical, and electric characteristics was the key objective of the study. The (CH3NH3)(2)MnCl4 compound crystallises in the orthorhombic system (Pccn space group). For the compound under study, the UV-visible spectroscopy spectrum shows the direct band-gap value of similar to 3.6 eV, indicating that it is a semiconductor material. The electric studies were conducted in a wide frequency range from 10(-1) Hz-10(6) Hz and a temperature range from 348 to 388 K. Nyquist plots revealed only a semicircle in the whole impedance spectra due to the effect of interior grains. The obtained results were analyzed by fitting the experimental data to an equivalent circuit model R//C//CPE. The Alternating current conductivity (sigma(AC)) follows Jonscher's power law. The fitting of sigma(AC) curves reveals that the activation energy is equal to 0.706 eV. The dominant transport mechanism is the CBH model in the temperature range from 348 to 388 K. Studies of the dielectric constant permittivity epsilon*(<bold>omega</bold>) confirmed that the relaxation process was thermally activated.