On-site Growth of Halide Perovskite Micro and Nanocrystals

A system and method for patterned growth of halide perovskite nanocrystals is disclosed. This method allows control over the size, number and position of the nanocrystals, while ensuring compatibility with device integration processes. The method uses a topographical template comprising a plurality of wells with asymmetric surface wetting to confine the nanocrystal growth to within the wells. Further, the shape and surface wetting properties of the wells are used to induce local directional forces to guide nanocrystal positioning during the growth process. With this technique, scalable arrays of nanocrystals with tunable dimensions and precise positional accuracy are possible. As an example, this method allows arrays of active nanoscale perovskite light emitting diodes (LEDs).