Patterning metastable photoluminescence shapes into mixed-halide perovskites using spatial laser beam shaping

We employ spatially tailored laser shapes to impress metastable photoluminescence pattern on mixed-halide perovskites thin-films. A novel two-dimensional deformable phase plate spatial laser shaper is integrated into a microscopy setup to investigate controllable patterning of light-induced halide segregation. Different spatial beam profiles demonstrate the controllability of the patterning method. The imprinted profiles show self-erasure within minutes, demonstrating metastability due to reversible remixing of segregated halides. Imprinted shapes are observed by spectrally separated photoluminescence imaging of mixed halide and iodide-rich phases in perovskite thin-films.