Halide perovskites have garnered significant attention over the past decade due to their remarkable optoelectronic properties. Perovskite light-emitting diodes (PeLEDs) have surpassed the 20% external quantum efficiency (EQE) limit for planar organic LED (OLED)-like device structures [1]. A bottom-up approach in perovskite material science highlights the potential of solution-processing techniques for device fabrication. Most high-efficiency PeLEDs reported to date have been fabricated using the spin-coating technique, which facilitates the integration of diverse materials [2]. However, spin coating is unsuitable for mass production, as it results in considerable material waste, with only a small fraction of the solution contributing to the thin-film.

Inkjet printing has emerged as a versatile and cost-effective alternative for fabricating perovskite-based devices. This technique offers high precision, scalability, and seamless integration with electronic and photonic components. Inkjet printing enables controlled deposition of materials, yielding uniform and high-quality perovskite films essential for efficient device performance. In 2020, the first PeLEDs with inkjet-printed perovskite layers were reported, achieving moderate efficiencies below 10% [3,4]. Subsequent advancements include the development of fully inkjet-printed PeLEDs [5], lead-free inkjet-printed PeLEDs [6], and the first fully inkjet-printed inorganic PeLEDs [7].

This paper reviews the key features of the inkjet printing technique, emphasizing its advantages over traditional methods, such as scalability, material efficiency, and precision in layer deposition. The discussion includes the fundamentals of solution-processing methodologies and the optimization of precursor formulations, highlighting the challenges in achieving uniform crystal formation and stable film morphology. Despite its potential, inkjet printing faces several limitations, such as coffee-ring effects, nozzle clogging, and difficulties in controlling film thickness and homogeneity across large areas. Addressing these challenges requires innovations in ink formulations, printing protocols, and the design of advanced hardware.

Additionally, sustainable strategies are examined, including the use of lead-free perovskites and eco-friendly solvents, which aim to reduce environmental impact while maintaining device performance. Examples of recent advancements are presented, such as fully inkjet-printed devices integrating all functional layers, which demonstrate the scalability and versatility of the technique. Future perspectives focus on the integration of inkjet printing into roll-to-roll manufacturing systems, enabling large-scale, cost-effective production of PeLEDs. These developments could unlock new opportunities for commercial applications, including flexible displays, wearable electronics, and next-generation lighting systems.