Making full-color active matrix display based on quantum dot light emitting diodes(AM-QLEDs) via ink-jet printing is attractive in display industry due to QLEDs' wide color gamut and their potential manufacturing ...Making full-color active matrix display based on quantum dot light emitting diodes(AM-QLEDs) via ink-jet printing is attractive in display industry due to QLEDs' wide color gamut and their potential manufacturing advantages of large screen size and low cost. The challenges for realizing AM-QLED display are how to achieve high quality films through ink-jet printing, multi-color patterning, electroluminescence(EL) color purity, and high efficiency. Herein, a 2-inch diagonal full-color AM-QLEDs display with pixel density of 120 pixels per inch(PPI) fabricated by ink-jet printing technique is presented. Driven by a metal oxide TFT(MOTFT) back-panel, the display exhibits a maximum brightness of 400 cd m.2, and a color gamut of 109%(NTSC 1931). The red, green, and blue(RGB) monochrome QLEDs passive matrix panels fabricated by ink-jet printing technique have a current efficiency(CE) of 2.5, 13.9, and 0.30 cd A.1, respectively. To the best of our knowledge, the efficiencies are the highest among passive matrix QLEDs panels made by ink-jet printing technique. The ink-jet printed QDs films show good thickness uniformity due to high viscosity and low volatility of the printable inks, and no cross-contamination between adjacent pixels resulting from the hydrophobic pixel defining layer.展开更多
The emergence of new display devices,such as organic light-emitting diodes,has brought about numerous advantages,including high material utilization,low cost,and high adaptability.These devices are manufactured using ...The emergence of new display devices,such as organic light-emitting diodes,has brought about numerous advantages,including high material utilization,low cost,and high adaptability.These devices are manufactured using inkjet printing and possess the potential to become a key technology for display transformations.However,a challenge in achieving this is the display effect that reveals uneven brightness and darkness,which can be avoided by controlling the volume of ink solution in a pixel to within 5%.Currently,the volume difference among the nozzles of commercial printheads does not meet the requirements for volume uniformity,thus challenging the printing process.Therefore,designing a suitable printing method that allows for the fusion of different volumes of ink droplets,ultimately reducing the error of the post fusion process,is necessary.In this study,we propose a print display droplet fusion scheduling method comprising two main steps.First,we use a dichotomous trust domain algorithm to obtain a feasible range of printhead docking point spacings for different nozzle and pixel panel resolutions.Second,we model the printing process as a droplet fusion scheduling model based on mixed integer programming,with the optimization objective of achieving intra pixel volume uniformity via ensuring the volume uniformity of ink droplets within all pixels.We verified this method through numerical simulations and printing experiments using 394 pixels per inch(ppi)pixel panels and successfully reduced the volume uniformity error among pixels to within 5%.展开更多
基金supported by the National Key Basic Research and Development Program of China (2015CB655004)the National Natural Science Foundation of China (U1601651, 51521002, U1301243, 61574061)the Educational Commission of Guangdong Province (2015B090914003, 2014KZDXM012)
文摘Making full-color active matrix display based on quantum dot light emitting diodes(AM-QLEDs) via ink-jet printing is attractive in display industry due to QLEDs' wide color gamut and their potential manufacturing advantages of large screen size and low cost. The challenges for realizing AM-QLED display are how to achieve high quality films through ink-jet printing, multi-color patterning, electroluminescence(EL) color purity, and high efficiency. Herein, a 2-inch diagonal full-color AM-QLEDs display with pixel density of 120 pixels per inch(PPI) fabricated by ink-jet printing technique is presented. Driven by a metal oxide TFT(MOTFT) back-panel, the display exhibits a maximum brightness of 400 cd m.2, and a color gamut of 109%(NTSC 1931). The red, green, and blue(RGB) monochrome QLEDs passive matrix panels fabricated by ink-jet printing technique have a current efficiency(CE) of 2.5, 13.9, and 0.30 cd A.1, respectively. To the best of our knowledge, the efficiencies are the highest among passive matrix QLEDs panels made by ink-jet printing technique. The ink-jet printed QDs films show good thickness uniformity due to high viscosity and low volatility of the printable inks, and no cross-contamination between adjacent pixels resulting from the hydrophobic pixel defining layer.
基金This work was supported by the National Natural Science Foundation of China(Grant No.51975236)the National Key Research and Development Program of China(Grant No.2018YFA0703203)Innovation Project of Optics Valley Laboratory(Grant No.OVL2021BG007).
文摘The emergence of new display devices,such as organic light-emitting diodes,has brought about numerous advantages,including high material utilization,low cost,and high adaptability.These devices are manufactured using inkjet printing and possess the potential to become a key technology for display transformations.However,a challenge in achieving this is the display effect that reveals uneven brightness and darkness,which can be avoided by controlling the volume of ink solution in a pixel to within 5%.Currently,the volume difference among the nozzles of commercial printheads does not meet the requirements for volume uniformity,thus challenging the printing process.Therefore,designing a suitable printing method that allows for the fusion of different volumes of ink droplets,ultimately reducing the error of the post fusion process,is necessary.In this study,we propose a print display droplet fusion scheduling method comprising two main steps.First,we use a dichotomous trust domain algorithm to obtain a feasible range of printhead docking point spacings for different nozzle and pixel panel resolutions.Second,we model the printing process as a droplet fusion scheduling model based on mixed integer programming,with the optimization objective of achieving intra pixel volume uniformity via ensuring the volume uniformity of ink droplets within all pixels.We verified this method through numerical simulations and printing experiments using 394 pixels per inch(ppi)pixel panels and successfully reduced the volume uniformity error among pixels to within 5%.
