Rheology-controlled microlithography of exceptionally stable perovskite nanocrystals for microdisplays

Abstract

Metal halide perovskite nanocrystals (PNCs) are promising candidates for color conversion layers in displays due to their excellent optoelectronic properties. However, their practical application has been hindered by the challenge of simultaneously achieving both stability and patternability. While PNC/siloxane resin composites have recently demonstrated improved stability, their inherently high viscosity poses a significant obstacle to solution-based processing, thereby limiting their applicability in advanced display systems. In this work, we report a sequential strategy to tailor the rheological properties of PNC/siloxane nanocomposites, enabling the fabrication of uniform nanocomposite films with tunable thickness and well-defined patterns. Initially, the viscosity of the nanocomposites is reduced to improve solution processability and facilitate the formation of uniform thin films. Subsequently, a siloxane-resin-pinning (SRP) process is employed to enhance the elastic behavior of the films, suppressing re-agglomeration and maintaining spatial uniformity during fabrication of heterostructures and microlithography. The optimized films achieve a high color conversion efficiency of 97.39 % from blue to green emission without the need for a blue-cutting filter, demonstrating their potential as quantum dot enhancement films for display applications. Moreover, the resulting PNC/siloxane nanocomposite patterns retain stable photoluminescence quantum yield for over 100 days under ambient air and aqueous environments. Furthermore, the patterns exhibit exceptional stability under high-temperature conditions with elevated humidity. Integration of vertically stacked green- and red-color conversion layers with micro-LEDs produces stable, natural white emission, highlighting their robustness and potential for next-generation displays.