Novel Micro-OLED technology with over 20K ppi resolution

From OLED displays to programmable lights and biosensors, organic semiconductors have found increasing applications since thin film devices were first reported in the 1980s. Recently, the rapid development of wearable electronics has led to the highest resolution of devices, enabling a vivid experience in near-eye displays such as real and updated tools.

In a review published in the journal Wearable Electronicsscientists from Germany and China summarized their systematic work to develop a technology compatible with photolithography for making ultra-high-resolution organic semiconductor devices.

“For inorganic semiconductors such as silicon, device sizes are approaching 1 nm using well-developed photolithographic technology, which enables the integration of 200 million transistors in an area of ​​just one millimeter ,” explains Wenchong Wang, a senior scientist at the University of Muenster.

“Unfortunately, due to the deterioration caused by UV light and the composition of natural products, photolithography technology cannot be used alone. Other methods of patterning, such as fine metal masks, have resolutions of only tens of micrometers, which reduces the number of devices in the square millimeter to hundreds.”

Considering the possibility of very high resolution, photolithography can be a suitable patterning method for organic materials if it can be done without compromising their performance. The researchers tackled this challenge by developing a strategy of “first surface patterning and then systematic growth.”

What this means is that the surface of the substrate is first lithography before organic materials are produced. Next, organic semiconductor molecules were added, allowing them to spread on the surface and be selectively implanted in selected areas, resulting in the formation of patterns and devices. of materials on substrates.

As a result, OLEDs with resolutions of more than 20K ppi were achieved, meeting the needs of next-generation displays.

“Our method avoids the damage caused by lithographic processes in organic semiconductors, which offers many advantages in terms of surface engineering and material solutions,” said Lifeng Chi, principal investigator of study and professor at Soochow University.

“The electronic devices of the future will require the monolithic integration of many processes on a chip, including information collection, transmission, processing, storage and display. Together with colleagues we, too, are working towards more advanced and efficient devices.”

Provided by KeAi Communications Co.