Flexible full-color AMOLED display: a display technology about to burst forth

LEDs have become the focus of the market, but we still hear news from time to time that AMOLED (active-matrix organic light-emitting diodes) have made some progress.

Researchers from the Flexible Display Center (FDC) at Arizona State University recently announced that they have successfully assembled the world's first full-color flexible AMOLED display prototype in collaboration with Universal Display. The prototype uses FDC's bond/de-bond production process and Universal Display's full-color, top-emitting phosphorescent OLED (organic light-emitting diode) technology materials (Figure 1).

To protect the flexible screen from stains, dust, liquids and other contamination, the researchers used a proprietary single-layer encapsulation technology also from Universal Display. The final assembly of the display uses materials and technologies developed by several other partners in the FDC Industry Alliance.

Figure 1. Researchers at Arizona State University’s Center for Flexible Displays demonstrated the first full-color flexible AMOLED display using a bond/de-bond production process and Universal Display’s patented single-layer encapsulation technology.

这款FDC的OLED原型显示屏尺寸为4.1英寸（可视区域对角线长3.8英寸），屏幕采用PEN衬底和QVGA分辨率（图2）。该原型显示屏采用320x240的RGB像素排列、像素密度为92 dpi，采用2T1C像素电路与低温非晶硅（a-Si）技术。屏幕所用材料包括Universal Display提供的磷光红、绿、蓝OLED材料。研究人员表示表示这种材料在降低功耗方面相比基于玻璃的AMOLED原件有显著提升。

In addition to the 5-mil DTF HS-PEN substrate, the display integrates an active-matrix array of thin-film transistors—made from DuPont's Teijin Films Teonex film using a substrate processing process developed by FDC. The researchers also produced another model whose transistors use low-temperature a-Si and high-performance InGaZnO technology.

The display prototype provides a brightness of 200cd/m2. Its color temperature is D6500, and the RGB values ​​are: R (0.463, 0.529), G (0.105, 0.576), B (0.088, 0.397).

Figure 2. FDC’s prototype uses a 3.8-inch OLED display with QVGA resolution and a brightness of 200 cd/m2.

Function

Funded primarily by the U.S. Army, FDC’s primary goal is to develop lightweight, bendable, damage-resistant OLED displays capable of displaying full-color video. These displays can withstand damage common in military applications.

An important feature that enables these flexible screens to work properly in harsh battlefield environments is Universal Display's single-layer encapsulation technology. A single encapsulation layer can provide enough protective barrier to separate the screen from the surrounding environment. More importantly, the material used for this barrier is environmentally friendly and can be manufactured at low cost.

“The demonstration of the first flexible color phosphorescent AMOLED screen that combines Universal Display’s packaging technology with FDC’s bond/de-bond production process represents a major step forward in the development of flexible OLED displays,” said Mike Hack, vice president of Universal Display and member of the FDC Board of Directors. “In addition to advancing the U.S. Department of Defense’s goals, flexible OLED displays have the potential to provide unlimited opportunities for commercial and consumer products for the foreseeable future.”

prospect

Compared with existing video display technology, the low power consumption characteristics of Universal Display's phosphorescent OLED display are very helpful for field applications. Although the specific power consumption value has not yet been disclosed, if the energy saving effect is significant, the prospects for flexible AMOLED displays in the commercial and consumer markets will be very bright.