Tolerance of metal halide perovskites to mechanical treatment enables the fabrication of patterned luminescence nano- and microstructures

Abstract

Metal halide perovskites have shown a great performance in a broad range of optoelectronic devices. The variety of preparation methods makes perovskites especially attractive, yet preparation of complex nanostructures based on these materials remains challenging. Here we present a template assisted method allowing to achieve any pre-designed arrangement of methylammonium lead triiodide (MAPbI₃) polycrystalline patterns with the spatial resolution defined by the template. We utilized a Si/SiO₂ wafer with circular 180 nm deep recesses with diameters ranging from 200 to 1600 nm as a template. A polycrystalline perovskite powder was obtained by scratching off a thin perovskite film and mechanically introduced into the patterned template as a pigment. Scanning electron microscopy revealed that the recesses are filled with tightly packed sub-20 nm crystallites. Considering that the spin-coated film used as a source of MAPbI₃ consisted of grains up to 2000 nm in diameter suggests that the initially prepared grains were crashed by rubbing to much smaller crystallites. In spite of this harsh mechanical treatment, the filled recesses showed a strong photoluminescence signal, demonstrating the applicability of this approach for the fabrication of diverse nanophotonic structures.