High-Resolution Multicolor Patterning of Metal Halide Perovskite Nanocrystal Thin Films through Rapid-Evaporation-Assisted Strategy

Material integrations with the desired shape, size, and dimension allow for the fabrication of high resolution and high performance devices. However, the patterning of all-inorganic halide perovskite nanocrystals (NCs), promising building blocks for optics and optoelectronics, has been a fundamental challenge owing to their unstable and reactive structures and properties. Here, a rapid-evaporation-assisted patterning strategy is reported that simultaneously pattern CsPbBr₃ NC thin films and tune the color by selectively printing the anion-exchange ink of micro-sized droplets. The rapid evaporation time is investigated according to the droplet size, falling into a range that is faster than the structural degradation time but slower than the chemical reaction time of anion exchange. Structural, chemical, optical analyses, and analytical estimation of droplet evaporation are conducted. As a result, high-resolution multicolor patterns with minimum feature size down to 5 µm and a pitch of <2 µm, covering the entire visible emission range, are achieved. It is believed that the multicolor patterning technique of PeNCs will significantly contribute to the development of next-generation devices, such as image sensors, displays, and other fields.