Progress on Inkjet Printing Technique for Perovskite Films and Their Optoelectronic and Optical Applications

Inkjet printing (IJP) as an emerging technology is expected to achieve a new generation of printable, low-cost, large-area, and high-performance perovskite optoelectronic devices. However, the coffee ring effect generated during inkjet printing and mutual solubility issues often lead to poor crystallization and uneven film thickness of printed perovskite films, thus deteriorating device performance. This mini review introduces classification and principles of IJP technology and printability of ink and then highlights several key strategies for achieving uniform high-quality perovskite films with inkjet printing. These strategies consist of developing stable ink formulations, improving substrate wettability, controlling droplet deposition, utilizing film pre- or post-treatment techniques, and so on. Finally, regarding the forefront and hotspots in the current research fields, this review summarizes the application progress of inkjet-printed perovskites in the optoelectronic fields of solar cells, lighting and display, and photodetectors and the optical fields consisting of anticounterfeiting and down-conversion films of light-emitting diodes (LEDs) or organic LEDs, and the review looks forward to the bright future of IJP technology for achieving different types of emerging perovskite optoelectronic and optical applications.