Misubishi makes OLED breakthrough

Mitsubishi Chemical Corporation and Mitsubishi Chemical Group Science and Technology Research Center, Inc. have announced that both companies have developed an Organic Light-Emitting Diode (OLED) device with the highest efficiency in the world in new blue phosphorescence OLED material.

The new OLED material, which can be produced by a lower-cost, wet-coating process, is expected to open the way to the development of a new class of large flat-panel displays.

Unlike LCD screens, OLED devices emit light when an electric current is applied and do not require a backlight to function. They consume less power, have a wider viewing angle and display a brighter image with a refresh rate that is a thousand times faster than LCDs.

MCRC has been developing materials, mainly phosphorescence-emitting layer material, suitable for manufacturing a thin, bright large-screen display. Phosphorescent material has four times greater luminous efficiency in principle than that of fluorescent material, which is widely employed now. This higher efficiency of phosphorescence leads to low power consumption, which is critical for applications using larger screens such as flat-panel television screens. In addition, the wet-coating method enables low-cost processing and makes practical the fabrication of large-area screens, which has been difficult and expensive using standard vacuum deposition processes.

The newly developed OLED device employs Mitsubishi’s own blue phosphorescence host material (wet-coating type), hole blocking material, and hole injection material to optimize the design of a device to achieve the current efficiency of 30 cd/A at the intensity of 100 cd/m2 (external quantum efficiency: 13%), more than twice that of conventional blue wet-coating type OLEDs.