Phase distribution control in thermally evaporated perovskite films for speckle-free laser imagingPhase distribution control in thermally evaporated perovskite films for speckle-free laser imaging

Thermal evaporation, a mature semiconductor fabrication technique, offers a viable route toward scalable production. However, to monitor the phase distribution of perovskites in thermally evaporated process is still challenging.

Here, we systematically investigated and regulated thermally evaporated FAXCs0.8PbBr3 perovskite films by tuning the FA content to optimize the phase distribution. At an intermediate FA content, the film exhibited a more balanced distribution of n = 2 to n = 5 quantum-well phases, which facilitated ultrafast carrier transfer (<0.31 ps) and suppressed nonradiative recombination. FA+ actively participates in the perovskite lattice as an A-site cation, contributing to more ordered crystallization and lower defect densities.