MMaterialsgateNEWS 2016/08/01

Related MaterialsgateCARDS

KAIST develops ultrathin, transparent oxide thin-film transistors for wearable display

With the advent of the Internet of Things (IoT) era, strong demand has grown for wearable and transparent displays that can be applied to various fields such as augmented reality (AR) and skin-like thin flexible devices.

However, previous flexible transparent displays have posed real challenges to overcome, which are, among others, poor transparency and low electrical performance. To improve the transparency and performance, past research efforts have tried to use inorganic-based electronics, but the fundamental thermal instabilities of plastic substrates have hampered the high temperature process, an essential step necessary for the fabrication of high performance electronic devices.

As a solution to this problem, a research team led by Professors Keon Jae Lee and Sang-Hee Ko Park of the Department of Materials Science and Engineering at the Korea Advanced Institute of Science and Technology (KAIST) has developed ultrathin and transparent oxide thin-film transistors (TFT) for an active-matrix backplane of a flexible display by using the inorganic-based laser lift-off (ILLO) method. Professor Lee's team previously demonstrated the ILLO technology for energy-harvesting (Advanced Materials, February 12, 2014) and flexible memory (Advanced Materials, September 8, 2014) devices.

The research team fabricated a high-performance oxide TFT array on top of a sacrificial laser-reactive substrate. After laser irradiation from the backside of the substrate, only the oxide TFT arrays were separated from the sacrificial substrate as a result of reaction between laser and laser-reactive layer, and then subsequently transferred onto ultrathin plastics (4μm thickness). Finally, the transferred ultrathin-oxide driving circuit for the flexible display was attached conformally to the surface of human skin to demonstrate the possibility of the wearable application. The attached oxide TFTs showed high optical transparency of 83% and mobility of 40 cm^2 V^(-1) s^(-1) even under several cycles of severe bending tests.

Professor Lee said, "By using our ILLO process, the technological barriers for high performance transparent flexible displays have been overcome at a relatively low cost by removing expensive polyimide substrates. Moreover, the high-quality oxide semiconductor can be easily transferred onto skin-like or any flexible substrate for wearable application."

Source: The Korea Advanced Institute of Science and Technology (KAIST) – 29.07.2016.

These research results, entitled "Skin-Like Oxide Thin-Film Transistors for Transparent Displays," were the lead article published in the July 2016 online issue of Wiley's Advanced Functional Materials.

References:

[1] Advanced Materials, February 12, 2014, Highly-efficient, Flexible Piezoelectric PZT Thin Film Nanogenerator on Plastic Substrates (http://onlinelibrary.wiley.com/doi/10.1002/adma.201305659/abstract)

[2] Advanced Materials, September 8, 2014, Flexible Crossbar-structured Resistive Memory Arrays on Plastic Substartes via Inorganic-based Laser Lift-off (http://onlinelibrary.wiley.com/doi/10.1002/adma.201402472/abstract)

Investigated and edited by:

Dr.-Ing. Christoph Konetschny, Inhaber und Gründer von Materialsgate
Büro für Material- und Technologieberatung
The investigation and editing of this document was performed with best care and attention.
For the accuracy, validity, availability and applicability of the given information, we take no liability.
Please discuss the suitability concerning your specific application with the experts of the named company or organization.

You want additional material or technology investigations concerning this subject?

Materialsgate is leading in material consulting and material investigation.
Feel free to use our established consulting services

MMore on this topic

Whether showing off family photos on smartphones or watching TV shows on laptops, many people look at liquid crystal displays (LCDs) every day. LCDs are continually being improved, but almost all currently use color technology that fades over time. Now, a team reports in ACS Nano that using aluminum nanostructures could provide a vivid, low-cost alternative for producing digital color. Conventional color technology used in displays is susceptible to photobleaching, or fading. So researchers have looked toward aluminum nanoparticles that can display colors in electronics, thanks to a property called “plasmon resonance.” To create plasmonic color devices, researchers group nanostructures... more read more

Professor Kyung-Cheol Choi and his research team from the School of Electrical Engineering at KAIST have developed fiber-like light-emitting diodes (LEDs), which can be applied in wearable displays.

The research findings were published online in the July 14th issue of Advanced Electronic Materials. Traditional wearable displays were manufactured on a hard substrate, which was later attached to the surface of clothes. This technique had limited applications for wearable displays because they were inflexible and ignored the characteristics of fabric. To solve this problem, the research team discarded the notion of creating light-emitting diode displays on a plane. Instead, they focused on fibers, a component of fabrics, and developed a fiber-like LED that shared the characteristics of both fabrics and displays. The essence of this technology, the dip-coating process, is to immerse... more read more

MaterialsgateNEWSLETTER

Partner of the Week

Search in MaterialsgateNEWS

Books and products

MaterialsgateFAIR:
LET YOURSELF BE INSPIRED