Toward Scalable Fabrication of High-Quality Metal Halide Perovskite Films Through Confined-Volume Printing

We have recently developed restricted-area printing by ink drawing (RAPID) of metal halide perovskite thin films. RAPID works by confining the volume of the precursor ink between a superstrate and substrate during printing, providing precise control over the ink environment; once the ink is no longer confined, the solvent evaporates and growth of the previously formed—and environmentally influenced—nuclei occurs rapidly. Using RAPID, the rate of perovskite nuclei formation can be limited, resulting in large grains and minimizing the grain boundary surface area known to be sites for nonradiative recombination and efficiency loss. In this presentation, we will introduce the RAPID technique and discuss our progress using it to control the microstructure and optoelectronic properties of metal halide perovskite thin films. We will highlight effects of superstrate temperature, confinement gaps, and print speeds as we move toward printing highly efficient and stable perovskite-based devices at speeds >1 m min^–1.