With the rapid development of artificial intelligence, image recognition, and 5G communication technology, augmented reality (AR) and virtual reality (VR) technologies are developing at an alarming rate. In the context of COVID-19, remote office and consumer interaction are on the rise. The market turns its attention back to AR/VR and increases its investment in technology applications.

One of the main reasons for the explosion in the market is the advancement of new display technology with excellent performance. As a staple of AR/VR, display devices must have ultra-high pixel density and fast refresh rate, as well as small volume and light weight. At present, liquid crystal display (LCD) and organic light-emitting diode (OLED), two main display technologies, have been applied to near-eye displays (NEDs) and head-mounted displays (HMDs). ). However, due to low conversion efficiency and color saturation, rapid aging, and short lifespan, the development of new display technologies has accelerated.

Micro-LED has excellent optical performance and long lifespan, which is considered to be the next generation and the latest display technology. The minimum pixel size reaches tens of microns and the high pixel density makes it suitable for AR/VR. Besides high pixel density, full color is also the key element to realize Micro-LED in AR/VR and color conversion scheme is an effective method. Quantum dots were deposited on ultraviolet or blue micro-LED chips using inkjet printing technology to achieve three-color luminescence and avoid mass transfer technology. In recent years, inkjet printing technology shows great potential in micro-manufacturing due to its advantages of digitization, pattern making, additive manufacturing, low material waste, and large-area printing. In particular, the emergence of super inkjet (SIJ) printing technology can achieve ultra-high resolution printing with a minimum printing line width in the submicron region. It sheds light on the fabrication of a high-resolution color conversion layer for micro-LEDs to realize full-color display, and in particular for augmented/virtual realities (AR/VR).

The authors of this article published in Optoelectronic advances overview of the principle of inkjet printing technique and its application in micro displays for AR/VR. In this review, the progress of AR/VR technologies is introduced first, followed by the discussion of the adaptability of micro-LED display technology in AR/VR and the advantage of printing a color conversion layer for micro-LEDs. using inkjet printing technology. The radiation-free energy transfer mechanism and the influence of color conversion layer thickness on color conversion efficiency are discussed. The advantages of SIJ over other printing technologies are presented in resolution.

In the second part, the printing principle of various inkjet printing technologies was introduced, as well as two key issues: optimization of ink rheological parameters and reduction of coffee ring effects. The rheological parameters of the ink suitable for each printing technology and the influence of the rheological parameters on the printing effect were introduced. Two solutions to the caffeine ring effect and specific enhancement methods were reviewed. Finally, some potential problems associated with the color conversion layer are highlighted, including light crosstalk, blue light absorption, and self-absorption effect. This review article serves as a reference for the areas of inkjet printing technologies, micro-LED full colorization, and their application in AR/VR.

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