Ultralong-life deep-blue fluorescent OLED device achieved by Recombination-Site Tailoring Injection

Ultralong-life deep-blue fluorescent OLED device achieved by Recombination-Site Tailoring Injection (ReSTI) technology


Harue Nakashima

Semiconductor Energy Laboratory Co., Ltd. (SEL),


We have discovered that using a specific material in the carrier-transport layer of an OLED device can control changes in carrier balance at the initial stage of the device being driven. This can inhibit initial degradation. This technology, which we call Recombination-Site Tailoring Injection (ReSTI) technology, enables control of the carrier recombination site using a specific material in the carrier-transport layer. We used this technology to drastically improve the lifetime of an OLED device. We have successfully developed an ultralong-life deep-blue fluorescent device with an external quantum efficiency (EQE) of 10and an LT95 exceeding 800 h at a current density of 50 mA/cm2.