Lead halide perovskites (LHP), APbX3, are being extensively explored in photovoltaics and in optoelectronic devices. Despite extensive investigations on LHPs, large scale application is held due to stability and toxicity concerns. Other promising alternatives include 2D analogues of 3D inorganic lead halide perovskites, referred as layered perovskites. These layered perovskites are being studied for various optoelectronic applications recently. Such layered perovskites with structural formula A3B2X9 (A = Cs+, Rb+; B = Sb3+, Bi3+; and X =Cl-, Br-, I-.) are lead free and stable. Detailed introduction to the structural, optical and vibrations properties of Rb3Sb2I9 layered perovskite in contrast to the LHPs will be discussed. Synthesis and characterization of Rb3Sb2I9 single crystals followed by preliminary results on high quality, micron sized single crystals of Rb3Sb2I9 will be presented. These crystals exhibit exceptional stability under ambient conditions and are stable up to 250 °C. Rb3Sb2I9 crystals are shown to exhibit self-trapped excitonic emissions (STE) as discerned from the broad photoluminescence with large Stoke’s shift. Vibrational analysis and temperature dependent photoluminescence studies performed through micro-Raman spectroscopy reveal a strong electron-phonon coupling in the lattice. A detailed proposal on further studies being planned will be listed in the end.