  We demonstrate patterning of metal surfaces based on lift-off of perovskite
nanocrystals that enables the fabrication of nanometer-size features without
the use of resist-based nanolithography. The perovskite nanocrystals act as
templates for defining the shape of the apertures in metal layers, and we
exploit the variety of sizes and shapes that can be controlled in the colloidal
synthesis to demonstrate the fabrication of nanoholes, nanogaps and guides with
size smaller than the wavelength of light in the visible spectrum. The process
can be readily integrated with standard lithography and etching techniques for
the creation of more complex structures.
