Organic electroluminescent device
摘要
說明書
According to Table 2, it was identified that the blue organic electroluminescent devices of Examples 1 and 2 using two types of host materials had excellent driving voltage and/or current efficiency, and particularly, exhibited more superior performance in terms of a lifetime, compared to the blue organic electroluminescent devices of Comparative Examples 1 to 3 using one type of host material.
In addition, it was identified that the blue organic electroluminescent devices of Example 1 in which two types of host materials included in the light emitting layer had a HOMO energy level difference of 0.13 eV and Example 2 in which the difference was 0.11 eV exhibited a significantly superior effect in terms of a lifetime while having similar driving voltage and current efficiency, compared to the blue organic electroluminescent device of Comparative Example 4 using two types of host materials having a HOMO energy level difference of Δ0.2 eV or greater.
Particularly, when comparing Examples 1 and 2 and Comparative Example 1, it was identified that Example 1, in which the first host material according to one embodiment of the present specification had a HOMO energy level of ?5.9 eV or lower and the second host material had a HOMO energy level higher than a HOMO energy level of the first host material by 0.1 eV to 0.2 eV, had a decreased driving voltage, and improved current efficiency, power efficiency and lifetime compared to Comparative Example 1 using a host material having a HOMO energy level of ?5.9 eV or lower alone.
Hereinbefore, preferred embodiments of the present specification have been described, however, the present disclosure is not limited thereto, and various modifications may be made within the scope of the claims and the detailed descriptions of the disclosure, and the modifications are also included in the scope of the present disclosure.
