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CEATEC 2025 (October 14 - 17)


CEATEC 2025 Shines Spotlight on Organic TFT-Driven LED Displays and Transparent Power-Generating Glass

CEATEC 2025, held at Makuhari Messe from October 14 to 17, showcased a variety of fascinating demonstrations centered on OLED and organic-TFT technologies. Here are some selected highlights, chosen from a personal and somewhat biased perspective.


China's DKE Exhibits a Wide Range of E-Ink Electronic Paper Modules


Pic 1. 28-inch color E-paper module
In the display module category, China-based DKE exhibited a large lineup of E-Ink (microcapsule-type electrophoretic) electronic paper modules, proudly displaying its extensive product range. Founded in 2005, DKE specializes in electronic paper modules and operates four factories in China and Vietnam. Its products span from compact 0.97-inch modules to large 42-inch modules, covering monochrome, full-color, and flexible types.

Photo 1 shows a wide-aspect 28-inch color module that appeared almost as vivid as an LCD. In Japan, Marubun serves as the distributor, focusing mainly on signage applications.

Full-Color LED Display Driven by High-Mobility Organic-TFTs


Pic 2. LED display with organic-TFT
Tokyo University startup Organocircuit presented a full-color LED display driven by organic-TFTs, demonstrating the application potential of high-mobility organic semiconductors. The organic semiconductor material used is C10-DNBDT, whose grains were grown up to centimeter scale using a proprietary coating crystallization technique. As a result, high mobility exceeding 10 cm2/V･s was achieved.

The showcased flexible panel measured 300 × 300 mm with 10,000 pixels. The bottom-gate bottom-contact type organic-TFTs were first formed on a glass substrate and then transferred to a PEN film for flexibility.

As an LED display, it offered high brightness, and the resolution was sufficient for distant viewing, making it appear practically suitable for lightweight signage applications. However, several bright and dark defects were observed. According to the exhibitor,“the defects originate from the organic-TFTs, and we are currently investigating the mechanism behind their occurrence.”

Yamagata University Demonstrates Simplified Fabrication of OLEDs


Pic 1. OLED with sprayed deposited emitting layer
Yamagata University, known for its annual stream of creative organic device proposals, demonstrated technology for more convenient fabrication of organic EL devices this year. One approach was spray-coating emissive layer, enabling large-area deposition while significantly reducing material waste compared to spin-coating.

As shown in Photo 3, this method produced highly uniform, bright organic EL devices. Electrical (I-V), optical (L-I), and lifetime characteristics were confirmed to be equivalent to those of spin-coated devices. The staff emphasized that “spray-coating costs less in materials and is much easier to handle.”


Fig.3 On demand patterning image of insulator film by IJ method
Another proposal was an on-demand organic EL patterning process for producing small quantities of monochrome EL devices easily. As illustrated in Figure 1, a UV-curable insulating material is printed by inkjet printing method onto a transparent electrode substrate to form an insulating pattern. The organic layers are then deposited by evaporation to complete the device.

Since areas with the insulating layer do not emit light, characters or images can be displayed in monochrome. The system functions as a desktop manufacturing tool, allowing one-of-a-kind organic EL designs to be produced easily.

Transparent Power-Generating Glass Based on Dye-Sensitized Solar Cells


Pic 4. Transparent power generation glass
At the Tokyo Bay eSG Project booth - an initiative led by the Tokyo Metropolitan Government to envision sustainable urban development for the next 50 to 100 years-three newly adopted projects were introduced. One of them, by inQs (Inks), featured transparent power-generating glass developed in-house.

Although detailed technical information remains undisclosed, the product is based on a dye-sensitized solar cell with a less porous TiO2 layer and nearly colorless sensitizing dyes, achieving over 70% visible light transmittance appearing nearly transparent to the eye.

Because it can generate power from both sides, the glass could be used in windows to harvest energy from sunlight and indoor light. However, the photoelectric conversion efficiency remains below 1%, limiting potential applications to low-power tasks such as real-time sensing.

Yokohama National University Proposes Ultra-Flexible Gas-Barrier Films Using Liquid Metal


Pic 5. Gas barrier film using liquid metal
Yokohama National University proposed ultra-flexible gas-barrier and thermal-conductive films utilizing liquid metal. The gas-barrier film consists of a Ga-In-Sn liquid metal layer sandwiched within an ultrathin TPU film, combining excellent gas-barrier properties with stretchability.

It demonstrated oxygen barrier performance below the detection limit of standard measurement equipment and superior water vapor barrier properties (WVTR:10-2g/m2/day) compared to conventional stretchable materials. Even when stretched by 50%, the initial resistance remained nearly unchanged, and the protective film prevents corrosion.


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