Jeonbuk National University (JBNU) faculty have developed the world’s first technology that can dramatically improve heat generation problems in LED devices.

The research team led by Professor Hong Chang-hee of the Department of Semiconductor Science and Technology announced that they have dramatically improved the heat-generation problem of LED devices using graphene, the so-called 'dream' material.

This research, carried out with support from the National Research Foundation of Korea's Basic Research Laboratory (BRL) program and the Center of Excellence program, was published under the title "Improved heat dissipation in gallium nitride light-emitting diodes with embedded graphene oxide pattern" in the recent issue of Nature's sister journal Nature Communications (February 5).

Until now, sapphire, the material most commonly used for LED substrates, has low thermal conductivity. When operated at high power, it could not adequately dissipate and spread the generated heat, causing semiconductor chips to be damaged and making it difficult to ensure reliability.

However, Hong's team used their independently developed 'graphene patterning process' to form a gallium nitride (GaN) thin film containing graphene on a sapphire substrate and succeeded in fabricating LED devices.
(Patterning process: a process that creates desired repetitive micro-patterns on a substrate)

Graphene, which has thermal conductivity more than ten times higher than copper, evenly releases and disperses heat generated within the device. This drastically lowers the temperature of the semiconductor chip and secures device stability.

With this developed technology, high-current operation is possible even in planar LEDs that generate a lot of heat, enabling high-power LED implementation. This technology is expected to be applicable not only to LEDs but also to power devices used in electric vehicles, solar cells, organic light-emitting devices (OLEDs), LED TVs and other consumer electronics.

In particular, the 'graphene patterning process' independently developed by Hong's team is not limited by substrate size or shape, enabling immediate mass production. It can be fabricated easily through high-temperature heat treatment, so commercialization is expected in the near future.

The technology has been the subject of a completed domestic patent application, and patent applications overseas, including in the United States, are also in progress.

Professor Hong Chang-hee said, "This research is the world's first case of applying graphene, which has attracted global attention as a dream material, to optical devices, and it is of great significance. We will strive to commercialize these research outcomes as soon as possible."

Meanwhile, graphene is a novel material that was first isolated by Professor Andre Geim and researcher Dr. Konstantin Novoselov at the University of Manchester in the UK, and they were awarded the 2010 Nobel Prize in Physics for that work. With a thickness of 0.7 nanometers (7 x 10^-10 m), strength 100 times that of steel, electrical conductivity more than 100 times that of copper, and the ability to transport electrons over 100 times faster than semiconductor silicon, graphene has drawn the greatest attention from the global academic community as a dream material.