Electron transport material and organic electroluminescent device comprising the same
The present invention relates to an electron transport material and an organic electroluminescent device comprising the material in an electron transport layer. The compounds according to the present invention as an organic electron transport material have faster electron transport property compared to a conventional electron transport material. Thus, a device comprising the compounds according to the present invention shows low driving voltage, high efficiency, and excellent lifespan property. Furthermore, the electron transport compounds have excellent color coordinate, and thus are effective in blue light-emitting.
1. An electron transport material comprising a compound represented by the following formula 1:
wherein
A 1 represents a substituted or unsubstituted pyridyl, a substituted or unsubstituted pyrimidyl, a substituted or unsubstituted triazinyl, a substituted or unsubstituted pyrazinyl, a substituted or unsubstituted quinolinyl, a substituted or unsubstituted quinazolinyl, a substituted or unsubstituted quinoxalinyl, a substituted or unsubstituted naphthyridinyl, or a substituted or unsubstituted phenanthrolinyl;
L 1 represents a single bond, or phenylene, biphenylene or naphthylene unsubstituted or substituted with deuterium;
R 1 represents a substituted or unsubstituted (C1-C30)alkyl group, or phenylene, biphenylene or naphthylene unsubstituted or substituted with deuterium;
R 2 represents hydrogen, deuterium, or a structure of formula 2:
or
R 2 , fused to the carbazole structure, forms a benzocarbazole ring;
R 3 represents hydrogen, deuterium, a halogen, a substituted or unsubstituted (C6-C30)aryl group, or a substituted or unsubstituted 5- to 30-membered heteroaryl group;
X represents O, S, NR 11 , or SiR 12 R 13 ;
R 4 , R 5 , and R 6 each independently represent hydrogen, deuterium, a substituted or unsubstituted (C6-C30)aryl group, or a substituted or unsubstituted 5- to 30-membered heteroaryl group;
R 11 to R 13 each independently represent a substituted or unsubstituted (C6-C30)aryl group, or a substituted or unsubstituted 5- to 30-membered heteroaryl group;
a, c, d, and e each independently represent an integer of 1 to 4; where a, c, d, or e is an integer of 2 or more, each R 2 , each R 4 , each R 5 , or each R 6 is the same or different;
b represents an integer of 1 to 3; where b is an integer of 2 or more, each R 3 is the same or different;
n represents an integer of 0 or 1;
m represents an integer of 1 or 2; and
the heteroaryl and heteroarylene groups contain at least one hetero atom selected from B, N, O, S, P(═O), Si, and P.
2. The electron transport material according to claim 1 , wherein the compound of formula 1 is represented by the following formula 3, 4, or 5:
wherein
A 1 , L 1 , R 1 , R 2 , R 3 , R 4 , R 5 , a, b, c, d, m, and n are as defined in claim 1 .
3. An electron transport material selected from the group consisting of the following compounds:
4. An organic electroluminescent device comprising the electron transport material containing the compound of formula 1 as defined in claim 1 , and a reducing dopant.
5. The organic electroluminescent device according to claim 4 , wherein the reducing dopant is one or more selected from the group consisting of an alkaline metal, an alkaline earth metal, a rare-earth metal, an oxide of an alkaline metal, a halide of an alkaline metal, an oxide of an alkaline earth metal, a halide of an alkaline earth metal, an oxide of a rare-earth metal, a halide of a rare-earth metal, an organic complex of an alkaline metal, an organic complex of an alkaline earth metal, and an organic complex of a rare-earth metal.