Toxic-free metal halide perovskites have become forefront for commercialization of the perovskite solar cells and optoelectronic devices. In the present study, for the first time we show that particular metal doping in CsGeCl 3 halide can considerably enhance the absorbance both in the visible and ultraviolet light energy range. By using DFT based first principles method Mn and Ni is doped at the Ge-site of CsGeCl 3 halide. We investigate the detailed structural, optical, electronic and mechanical properties of all the doped compositions theoretically. The study of optical properties exhibits that the absorption edge of both Ni and Mn-doped CsGeCl 3 is shifted toward the low energy region (red shift) relative to the pristine one. An additional peak is observed for both doped profile in the visible light energy region. The study of mechanical properties ensures that both the doped samples are mechanically stable and ductile as the pristine CsGeCl 3 . The study of electronic properties shows that the excitation of photoelectrons is easier due to the formation of intermediate states in Mn-doped CsGeCl 3 . As a result Mn-doped CsGeCl 3 exhibits higher absorptivity in the visible region than the Ni-doped counterpart. A combinational analysis suggests that CsGe 1-x Mn x Cl 3 is the best lead free candidate among the inorganic prsovskite materials for solar cell and optoelectronic applications.

Metal halides with low‐dimensional molecular structures are the rising stars in the horizon of functional materials research. Among them, 1D metal halide hybrids are very promising for future optoelectronic applications because of their unusual photophysical properties resulting from strong quantum confinement. In the past few years, besides lead‐based 1D metal halide hybrids, research has been extended to lead‐free organic and all‐inorganic metal halides. Due to near‐unity photoluminescence quantum yield and excellent structural stability, all‐inorganic 1D metal halides are suitable for environmentally friendly optoelectronic devices. Moreover, the distortion and connectivity mode of metal halide octahedra arouse the formation of self‐trapped excitons within 1D metal halides, thus endowing the materials with distinct optical properties. Recent investigations have revealed many exciting characteristics of this new class of materials, such as ferroelectricity, ferromagnetism, optical cooling, and so on. This perspective presents not only structure–property correlations and recent applications of 1D metal halides but also the existing challenges and future research directions.

This work summarizes that RbSnX3 (X = Cl, Br, I) exhibits remarkable ductility and absorption in the ultraviolet (UV) region of the electromagnetic spectrum compared to those of CsBX3 (B = Ge, Sn, Pb; X = Cl, Br, I) metal halide perovskites.