Research Progress on the Preparation of OLED Based on the Inkjet Printing

Abstract Over the past few decades, organic light‐emitting diodes (OLEDs) have demonstrated compelling technological advantages due to their ability to directly convert electrons into photons without requiring backlighting, thereby offering self‐emissive surfaces, ultrathin device profiles, compatibility with flexible substrates, high luminance, and exceptional contrast ratios (achieving true black). Today, OLEDs dominate the market for small‐scale displays such as smartphones and laptops. Propelled by the burgeoning ubiquity of the Internet of Things, OLEDs are poised to experience an exponential upsurge in prospective exigency. However, conventional thermal evaporation techniques face challenges in achieving uniform large‐area OLED fabrication, rendering mass production costly and complex—a persistent drawback hindering OLEDs from becoming the undisputed market leader. Amidst this milieu, inkjet printing (IJP) has magnetized considerable scholarly and commercial traction across the panoply of fabrication modalities, crystallizing as the pre‐eminent candidate for scalable, large‐area OLED manufacturing. This technique boasts non‐contact processing, high material utilization, and compatibility with roll‐to‐roll manufacturing. In this review, the critical parameters governing ink formulation are delineated and provide an overview of prevailing OLED device architectures. Subsequently, recent advancements are consolidate in inkjet‐printed OLED layers, culminating in a circumspect prognosis of the extant impediments and the prospective trajectory toward wholly inkjet‐patterned OLED architectures.