Assoc. Prof. Toshinori Matsushima (Molecular photoconversion Devices Division at International Institute for Carbon Neutral Energy) and Prof. Chihaya Adachi and their research group at Kyushu University have developed micrometer-thick organic light - emitting diodes that could improve the affordability and viewing angles of high-performance displays and televisions in the near future.

Organic light-emitting diodes (OLEDs) use layers of organic molecules to efficiently convert electricity into light. The molecules, though great emitters, are generally poor electrical conductors, so the name of the game has been thin—as in 100 nm, or about 1/500 the thickness of a human hair. Only by using such thin layers can electricity easily reach where emission occurs in the middle of devices. While extremely thin layers benefit from needing only a small amount of material, the use of such thin films complicates the reliable fabrication of millions of pixels since extremely small defects can cause device failure. Furthermore, light reflecting between the front and back of the thin layers often results in interactions—called cavity effects—that slightly distort the emission color at large viewing angles. Thus, the challenge has been to make the devices thicker while avoiding the drawbacks of organics. To do this, researchers at Kyushu University turned to an alternative class of materials called perovskites, which are defined by their distinct crystal structure.

For further information, please see the links below.

Kyushu University Homepage 

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Nature Online 

DOI: 10.1038/s41586-019-1435-5

Title:“High performance from extraordinarily thick organic light-emitting diodes”.

Authers: Toshinori Matsushima, Fatima Bencheikh, Takeshi Komino, Matthew Leyden, Atula S. D. Sandanayaka, Chuanjian Qin, and Chihaya Adachi.