A 403‐ppi (pixel per inch) real RGB active‐matrix organic light‐emitting diode (AMOLED) was fabricated without using fine metal mask (FMM). Organic light‐emitting materials were printed on array panel, with a novel process that has the advantages of low cost and high pixel density. The uniformity of the organic light‐emitting diodes (OLEDs) was improved with carefully tuning printing parameters, and good panel performance was achieved. The key to such a process was the design of the hexagonal patterning of the pixels. The image quality of the panel with this hexagonal pixel arrangement was evaluated with a bmp format Pixel Layout Simulation picture.

With the ever-growing demands for larger size and high resolution displays, Micro-light-emitting diode (Micro-LED) display with quantum dots (QDs) film as color conversion layers (CCLs) has become one of the most promising candidates of future display for its advantages in low power consumption and wide color range. In this study, we report a novel full-color display based on blue Micro LED, which has patterned red and green QDs color conversion (QDCC) layers fabricated by inkjet printing (IJP). A structure of double-layer bank was designed to reduce color deviation, prevent crosstalk, and flatten the QDCC layer. By optimizing the thickness of the red/green QDCC layers and the wavelength of blue Micro LED backlights, a full-color QDCC-LED display with 228 PPI resolution and size of 1.11-inch was successfully fabricated and showed superb performance. We not only effectively reduced crosstalk, but also improved the color conversion efficiency of QDs. In addition, this QDCC-LED display prepared by embedded bonding process shows a color gamut of 107.53% NTSC. Graphical Abstract

Active Matrix displays on light weight, non-fragile, plastic substrates are of great interests for portable applications. One of the challenges has been device performance processed at low temperature: in both carrier mobility and operation stability. Another challenge has been bonding-debonding efficiency. IGZO TFT array was fabricated on a lamination-based polyimide (PI) flexible substrate at 200 ºC and is easily debonded without additional equipment. Good electrical characteristic and high stability of the IGZO TFT have been demonstrated.

A 403ppi (pixel per inch) real RGB AMOLED was fabricated without using Fine Metal Mask (FMM). Organic light-emitting layer material was printed on array panel, resulting in a novel process with low cost and high pixel density. The OLED materials printed uniformly and the OLED device performed good property. The profile of the pixel was designed as a hexagonal pattern. Based on this design, it is possible to achieve 403 ppi real AMOLED using pixel printing process. The image quality for this hexagonal pixel arrangement was evaluated by a bmp format Pixel Layout Simulation picture.

Reflectivity, one of the most key specifications for display, is pursued to be extreme low to match the name of ultimate display for micro-LEDs. Conventionally, black light shield film is fabricated by photolithographic process before or after the micro- LED chips being mass transferred to the driver substrate to meet this requirement. In this study, we report a novel black light shield film material by a simple and effective graphical process to achieve ultra-low reflectivity with little influence on the light output of LED chips to dispense with complicated lithography process, which can fill the gap between the LED chips and the eutectic layer at the bottom of the LED chips, and expose the top of the micro-LED chips simultaneously. The black light shield film was directly adhered to the micro-LED substrate by heating, vacuum and press. Whole surface ashing process was then carried out to remove the excess black light shield film on the surface of the micro-LED substrate. By optimizing the thickness of removed black film, the surface of the micro-LED chips could be exposed while other places were still covered with black light shield film. A full-color Micro-LED display with 114 PPI resolution and size of 1.98-inch was successfully fabricated and showed superb performance with 1.16% reflectivity.