Color Tunable Stacked QD-OLED Hybrid Devices

Organic light-emitting diodes (OLEDs) and quantum dot light-emitting diodes (QLEDs) stand out as highly promising display technologies due to their notable advantages, including high efficiency, rapid response speed, and a high contrast ratio. Typically, flat panel displays incorporate distinct red, green, and blue subpixels placed side-by-side to replicate a full spectrum of colors. However, this design exhibits drawbacks such as a low geometric fill factor, reduced efficiency, and challenges in fabricating high-resolution displays. A potential solution to address these limitations lies in a multicolor-emitting pixel structure, enabling the selective emission of more than two colors from a single pixel. AC-driven color-tunable devices present a promising avenue to achieve this goal. In an AC tandem device, the emitted light's color is determined by the applied signal's polarity, resulting in different colors emitted under forward and reverse bias voltages. In this presentation, we introduce AC-driven multi-color OLED-QDLED hybrid pixel structures. The foundational unit comprises two-pixel QDLEDs, fabricated using an inkjet process, with an OLED layer deposited atop these QDLEDs. Through the combination of these three pixels, a full-color display is achieved. Efficiency optimization is achieved by fine-tuning the materials and structures within the charge transport and charge generation layers. This device configuration features two horizontally arranged pixels and another vertically stacked pixel, enhancing the fill factor by 1.5 times. As a result, this approach holds promise for future display applications, offering high efficiency and resolution.