62‐3: Design of High‐Performance Tandem Blue Devices for Quantum‐Dot OLED Display

Abstract

Highly efficient tandem blue OLEDs based on fluorescent materials were developed for quantum dot OLED applications. We optimize the optical micro‐cavity structure for maximal efficiency, and the dependence of luminescence on the thickness uniformity is theoretically and experimentally confirmed with two different type of blue emitters. We also demonstrate that the selection of charge generation layer (CGL) and electrontransporting material adjacent to CGL have significant impact on the electroluminescence performance of the tandem blue OLEDs. Here, a two‐stack tandem blue OLED achieves a current efficiency of 13.3 cd/A with a CIE coordinate of (0.137, 0.047) and a blue index (BI) of 287, which is approximately 1.7 times higher than that of single unit.

23‐1: Invited Paper: Single and Tandem OLED Display Technologies with High Efficiency and Long Lifetime

“…Table 3 summarizes the BIs at 10 mA/cm 2 . The BI of the tandem OLED (B) was achieved 320, which is significantly high value [10]. This is attributed to both high efficiency blue dopant material and TE tandem OLED device with appropriate cavity condition.…”

“…The TE tandem OLED technology is one of useful candidates for noticeably high efficient and long lifetime OLED display [6,9,10].…”

“…Therefore, the progress of both the current efficiency and the lifetime is significantly important. For one of solutions, the adoption of the TE tandem OLED technology (tandem OLED) is certainly useful [6,9,10], and we have already started the development of the tandem OLED.…”

62‐2: Flexible Full‐Color Active‐Matrix Quantum‐Dot OLED Display

“…In our previous work, a highly efficient two-stack tandem B-OLED device as shown in figure 3(D) has been proposed and developed according to the trade-off between electroluminescence (EL) efficiency and process uniformity of blue dopant introduction [8] . The results show that in the same case of ±3% thickness fluctuation range derived from evaporation tools, the maximum reduction in blue index (defined as the current efficiency divided by the CIE-y value) of different blue dopants changed a lot from 17% to 36%.…”

77‐4: Highly Efficient Side‐by‐Side Three‐Stack Tandem Flexible OLED Displays with Yb‐doped n‐CGLs

“…Until now, there have been reports on improving current efficiency using SBS two-stack tandem OLED structure [3,4], but only simulated data has been disclosed regarding SBS three-stack tandem OLED structure [5,6]. SBS three-stack tandem OLEDs may show tripled driving voltage of single OLEDs, so it is first necessary to verify the driving voltage.…”