“…Recently, single source thermal evaporation of CsPbBr 3 precursor material, prepared by a common solution-based multistep approach, was reported to yield films consisting of a mixture of CsPbBr 3 , CsPb 2 Br 5 and Cs 4 PbBr 6 compounds requiring mild post deposition treatments to obtain full conversion to CsPbBr 3 [51]. Therefore, post-deposition annealing of the CsPbBr 3 films deposited by thermal evaporation is a key post-growth step to improve quality and solar cell conversion efficiency [10,40,52]. On the other hand, although single-source vapor deposition is performed using mechano-chemically synthesized halide perovskite powders, different evaporation rates of the multiple components of the compacted target may cause off-stoichiometric transfer.…”