Light-emitting element, light emission apparatus, authentication apparatus, and electronic machine

1. A light-emitting element comprising:

an anode;

a cathode; and

a light emission layer arranged between the anode and the cathode and configured to emit light by energization between the anode and the cathode,

the light emission layer including a compound represented by a general formula NIR-D as a light emission material and a compound represented by a formula IRH-1 as a host material of the light emission material,

the general formula NIR-D being

wherein each R independently indicates group comprising a phenyl group, a thiophenyl group, a furyl group, or at least one species of derivatives thereof,

the formula IRH-1 being

wherein n indicates a natural number 1 to 12, and each R independently indicates a hydrogen atom, an alkyl group, an optionally substituted aryl group, or an arylamino group.

2. The light-emitting element as set forth in claim 1 , wherein

the host material is a compound represented by a formula IRH-2, which is

wherein R 1 to R 4 each independently indicate a hydrogen atom, an alkyl group, an optionally substituted aryl group, or an arylamino group, and R 1 to R 4 are the same as one another or different from one another.

3. The light-emitting element as set forth in claim 1 , wherein

the host material is a compound represented by a formula IRH-3, which is

wherein R 1 and R 2 each independently indicate a hydrogen atom, an alkyl group, an optionally substituted aryl group, or an arylamino group, and R 1 and R 2 are the same as one another or different from one another.

4. The light-emitting element as set forth in claim 1 , wherein

the host material is constituted of carbon atoms and hydrogen atoms.

5. The light-emitting element as set forth in claim 1 , wherein

a content of the light emission material in the light emission layer is 0.5 wt % to 5.0 wt %.

6. The light-emitting element as set forth in claim 1 , further comprising

an electron transport layer arranged between the light emission layer and the cathode and including a compound that has an anthracene skeleton.

7. The light-emitting element as set forth in claim 6 , wherein

the electron transport layer has a first electron transport layer including an azaindolizine-based compound that has an azaindolizine skeleton and the anthracene skeleton in a molecule, and a second electron transport layer arranged between the first electron transport layer and the light emission layer and including an anthracene-based compound that has an anthracene skeleton in a molecule and is constituted of carbon atoms and hydrogen atoms.

8. The light-emitting element as set forth in claim 7 , wherein

a thickness of the second electron transport layer is greater than a thickness of the first electron transport layer.

9. The light-emitting element as set forth in claim 7 , wherein

a thickness of the second electron transport layer is 30 nm to 150 nm.

10. The light-emitting element as set forth in claim 6 , wherein

a thickness of the electron transport layer is 55 nm to 200 nm.

11. The light-emitting element as set forth in claim 1 , wherein

a thickness of the light emission layer is 10 nm to 50 nm.

12. The light-emitting element as set forth in claim 1 , wherein

the light emission material is a compound represented by a formula IRD-4, which is

13. The light-emitting element as set forth in claim 1 , wherein

the light emission material is a compound represented by a formula IRD-5, which is

14. A light emission apparatus comprising the light-emitting element as set forth in claim 1 .

15. An authentication apparatus comprising the light-emitting element as set forth in claim 1 .

16. An electronic machine comprising the light-emitting element as set forth in claim 1 .