Since a decade, organo-metal trihalide perovskite (OTP) materials have received considerable attention owing to their distinct advantages of high-performance in solar cell application. However, few problems need to be resolved with respect to their commercialization; which includes (1) The OTP structure associated with toxicity of Pb atoms, (2) Long term durability and (3) cost-effectiveness. Until now, the highest efficiency obtained from lead-based perovskites. However, the utilization of Pb-based materials in solar cells is restricted due to their toxicity.^[1] In order to overcome this issue, majority of research progressing on lead free based compositions with attempt to achieve improved stability.

To investigate new generation of advanced materials, which are rarely reported so far, we synthesized a few organic inorganic perovskite compositions. Present investigation is therefore an exploratory study based on recent developments in organic-inorganic perovskites. Recently the research study reviewed the progress of lead free OTP.^[2] We successfully synthesized Cu-based ABX₃ type materials, i.e. CsCuCl_3, CH₃NH₃CuCl₃ and their crystallization, optical properties using different characterization tools, including crystal structure, photophysical (optical-thermal properties) and surface morphology. Lead free organic-inorganic perovskite structures have emerged as a class of optoelectronic materials.

Lead (Pb) halide perovskite structures have been splendid extensively in the area of perovskite solar cells, and consequently, various Pb based perovskite compositions were explored to enhance photon conversion efficiency. However, the toxicity associated with Pb persuade B-site metal cation substitution mostly take place with nearby bivalent metals of the same group (Sn and Ge). On the other hand, transition metals (Fe, Co, and Cu) can play a crucial role to decrease the bandgap upon B-site substitution and enhances the optoelectronic properties. Herein, we demonstrate the impact of B-site metal cation substitution with the use of Cu over lead halide perovskite materials by providing experimental and theoretical characteristics. We explored synthesis methodology for CsPbCl3, MAPbCl3, CsCuCl3 and MACuCl3. The physicochemical characterization (crystal structure and surface morphology analysis; thermal properties and optical properties) of these synthesized materials have been discussed and projected their impact with electronic band structure and DOS.

In summary, it describes the successful synthesis of lead free organo-metal trihalide perovskites (OTP), such as CsCuCl_3, CH₃NH₃CuCl_3, which can be established as non-toxic, cost effective and high-performance alternatives to lead based materials for solar cell applications. The optical properties determination revealed lower band gap and broad light absorption, suggesting that OTP materials can work under visible light and can harvest solar energy efficiently. The synthesized OTP would be explored as a potential candidate for solar cells and solar fuel applications.