Transition metal substituted all inorganic lead free halide perovskite (Cs2CuBr4) nanocrystals
Hybrid and all inorganic halide perovskites are of great scientific interest these days because of their excellent optoelectronic properties, like its easy bandgap tunability, higher molar exciton coefficient and lower exciton binding energy, making these materials useful for optoelectronic device applications. From the past two decades or even more lead halide perovskite materials, especially CH3NH3PbI3 has been tested, and been proved time and again, as an excellent solar absorber layer for perovskite solar cells, due to its conveniently small band gap and lesser exciton binding energies. Though the device performance and properties of this material makes it shine as a choice for numerous optoelectronic devices, the issue of lead toxicity and ambient instability persists, creating a huge hindrance in the path of its commercialisation as the same. Besides, the dimensionality confinement in perovskite leads to certain changes in its physical properties, like band gap tailoring, luminosity enhancement, etc., due to the quantum confinement effect and more. In the present work, we have endeavoured the synthesis of transition metal (Mn2+ and Co2+) doped all inorganic lead free halide perovskite (Cs2CuBr4) nanocrystals (NCs), followed with their photo-physical study, to check whether these materials are capable of achieving what their lead based counterparts have already achieved. We will also be looking at the band gap tunability and other physical properties, that come bundled when we dope transition elements within the lattice of halide perovskites.
Keywords: perovskites, lead free, transition metal doping, nanocrystals