Optimizing Slot Die Coating Process for High Quality Perovskite Thin Films

Metal halide perovskites have attracted considerable interest owing to their remarkable optoelectronic properties, including superior light absorption, exceptional defect tolerance, long carrier diffusion length and a highly tunable bandgap. These intrinsic characteristics, combined with high power conversion efficiency (PCE) and low manufacturing costs, position perovskites as promising candidates for the development of next-generation photovoltaic technologies. However, transitioning from laboratory-scale devices to large-scale manufacturing requires synthesis of perovskite thin films using scalable fabrication techniques.
Slot-die coating has emerged as a leading method for scalable synthesis of perovskite thin films. The coating parameters, such as header speed, slot gap, manifold, and lip geometry, can critically impact the quality of the synthesized films, including the lateral uniformity, surface roughness and defect densities.
In our work, we examine the correlation between the coating parameters and perovskite film quality. We employ metrology techniques, such as scanning electron microscopy, spectroscopic ellipsometry, time resolved photoluminescence and photoluminescence mapping to evaluate the quality of slot die-coated perovskite films. These techniques provide insights into the film’s thickness, optical properties and electrical performance enabling further optimization of the coating process.