Toshiba has developed an OLED component for lighting with a luminous efficiency of up to 91 lm/W. As a large-area illumination OLED element having a size of 8 cm × 7 cm, very high luminous efficiency is achieved.
The luminous efficiency of OLED components exhibited by Toshiba at the exhibition in March 2012 was 60 lm/W. On this basis, Toshiba uses various improvements, such as (1) changing the material of the electron transport layer, (2) adding metal auxiliary wiring to the ITO as a transparent electrode, and (3) removing the back electrode (cathode) material from the original. The aluminum (Al) used is changed to other materials having a high reflectance, and the luminous efficiency is greatly improved.
With the two means (1) and (2), the luminous efficiency was increased to 78.6 lm/W under the condition of an initial luminance of 1000 cd/m2. Moreover, the operating voltage is significantly reduced to 3.14V from the original 3.62V. Further, with (3), the luminous efficiency was further increased to 91 lm/W under the condition that the initial luminance was 1000 cd/m2.
Bringing a lot of room for performance improvement
In fact, the means in (1) ~ (3) are not new technologies. However, Toshiba's biggest feature is that it does not use the recent "popular technology", but achieves large-area, high-efficiency and low-voltage operation with simple component construction and standard luminescent materials.
In order to obtain high luminous efficiency, other companies use techniques that improve light extraction efficiency on the surface of components. For example, a method of adding a high refractive index layer in the vicinity of a transparent electrode and forming a unique light extraction layer on the surface of the element.
Toshiba first disclosed the component at the 2012 International Conference SID International Symposium, Seminar & Exhibition held in June 2012. At that time, "competitor technicians also encouraged that such a simple component can achieve such high luminous efficiency, which means that OLED components have sufficient space to improve luminescence performance, and it is possible to use recent new technologies in the future. Bringing the luminous efficiency close to the level of the LED" (Yuji Research and Development Center Display Foundation Technology Laboratory Manager Yu Gonggong).
Shenzhen Kaixuanye Technology Co., Ltd. , https://www.icoilne.com