Light emission material and organic electroluminescence device including the same
AssigneeSamsung Display Co., Ltd.
InventorsJunta Fuchiwaki, Tohru Sato
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Abstract
A light emission material includes a first compound satisfying Equation 1: K2≥0.1K1. Equation 1 In Equation 1, K1 is a sum of radiationless transition rate due to internal conversion from a certain specific n-th triplet excitation state to a lower order triplet excitation state including the lowest triplet excitation state, K2 is a reverse intersystem crossing transition rate from the certain specific n-th triplet excitation state to a singlet excitation state which is adjacent to the n-th triplet excitation state, and n is an integer of 2 or more. An organic electroluminescence device including the light emission material may simultaneously attain high emission efficiency and roll-off reduction.
Claims23
A light emission material comprising a first compound satisfying the following Equation 1:
- K2≥0.1K1, Equation 1
- wherein K1 is a sum of radiationless transition rate due to internal conversion from a certain specific n-th triplet excitation state to a lower order triplet excitation state including the lowest triplet excitation state, and K2 is a reverse intersystem crossing transition rate from the certain specific n-th triplet excitation state to a singlet excitation state, which is adjacent to the n-th triplet excitation state, and
- n is an integer of 2 or more.
An organic electroluminescence device, comprising:
- a first electrode;
- a hole transport region on the first electrode;
- an emission layer on the hole transport region;
- an electron transport region on the emission layer;
- and
- a second electrode on the electron transport region, wherein the emission layer comprises a first compound satisfying the following Equation 1:
- K2≥0.1K1, Equation 1
- wherein K1 is a sum of radiationless transition rate due to internal conversion from a certain specific n-th triplet excitation state to a lower order triplet excitation state including the lowest triplet excitation state,
- K2 is a reverse intersystem crossing transition rate from the certain specific n-th triplet excitation state to a singlet excitation state adjacent to the n-th triplet excitation state, and
- n is an integer of 2 or more.
Dependencies are inferred from the claim text.