The need of high quantum efficiency and stable semiconductor for the photovoltaics are always highly required. In this work, four phase containing multiphase bimetallic iodide (MPBI) compound was synthesized at room temperature by simple and novel chemical route. Synthesized compound was studied for structural, optical, and morphologic properties. The compound structural and phase confirmation was done by XRD, FT-IR, Raman spectroscopy and TEM studies. Optical properties such as absorption and emission characteristics were studied by UV-Visible spectroscopy and fluorescent spectroscopy respectively. The surface morphology and the elemental composition mapping was carried out using SEM and TEM methods. The detailed characterization inferred that high-temperature stable phase Ag4PbI6 was stabilized at room temperature along with AgI, PbI2 and Ag. From the obtained results, the mechanism of Ag4PbI6 phase formation is proposed and discussed. The synthesized semiconductor compound was studied for solar cell applications and obtained efficiency is 5.14 %. Further, the experimental solar cell results were verified using simulation results. This is one of the very few works which reports on room temperature stabilized high temperature stable Ag4PbI6 phase containing multiphase compound.