Organic electro-luminescent element and bioinstrumentation device

Patent metadata

Field	Value
Publication number	US-10228328-B2
Application number	US-201715823599-A
Country	US
Kind code	B2
Filing date	Nov 28, 2017
Priority date	Nov 30, 2016
Publication date	Mar 12, 2019
Grant date	Mar 12, 2019

Abstract

An organic EL element having a luminescence peak in a near-infrared range comprises a positive electrode, a negative electrode, and at least one organic layer including a luminescent layer located between the positive electrode and the negative electrode. The luminescent layer comprises a host material, a delayed fluorescent material and a luminescent material. The LUMO and HOMO energy levels of the delayed fluorescent material and the luminescent material, the absorption spectrum of the luminescent material, and the emission spectrum of the delayed fluorescent material satisfy predetermined relationships.

First claim

The invention claimed is:

1. An organic electro-luminescent element having a luminescence peak in a near-infrared range, comprising a positive electrode, a negative electrode, and at least one organic layer including a luminescent layer located between the positive electrode and the negative electrode,
wherein the luminescent layer comprises a host material, a delayed fluorescent material, and a luminescent material, and
wherein the delayed fluorescent material and the luminescent material satisfy relationships (1) to (4) shown below:
ΔHOMO+ΔLUMO≤0.6 eV  (1);

|ΔHOMO|≤0.4 eV  (2);

|ΔLUMO|≤0.4 eV  (3); and

| P Abs −P Em |≤30 nm  (4),

wherein “ΔHOMO” represents a value of a highest occupied molecular orbital (HOMO) energy level of the luminescent material minus a HOMO energy level of the delayed fluorescent material, wherein “ΔLUMO” represents a value of a lowest unoccupied molecular orbital (LUMO) energy level of the delayed fluorescent material minus a LUMO energy level of the luminescent material, wherein P Abs represents a maximal value at the longest wavelength side of an absorption spectrum of the luminescent material, and wherein P Em represents a maximal value at the longest wavelength side of an emission spectrum of the delayed fluorescent material.

2. The organic electro-luminescent element according to claim 1 , wherein ΔHOMO+ΔLUMO in the relationship (1) is 0.5 eV or less.

3. The organic electro-luminescent element according to claim 1 , wherein ΔHOMO+ΔLUMO in the relationship (1) is 0.4 eV or less.

4. The organic electro-luminescent element according to claim 1 , wherein the absolute value of ΔHOMO in the relationship (2) is 0.3 eV or less.

5. The organic electro-luminescent element according to claim 1 , wherein the absolute value of ΔLUMO in the relationship (3) is 0.3 eV or less.

6. The organic electro-luminescent element according to claim 1 , wherein the absolute value of P Abs −P Em in the relationship (4) is 25 nm or less.

7. The organic electro-luminescent element according to claim 1 , wherein the absolute value of P Abs −P Em in the relationship (4) is 20 nm or less.

8. The organic electro-luminescent element according to claim 1 , wherein the absolute value of P Abs −P Em in the relationship (4) is 0.15 nm or less.

9. The organic electro-luminescent element according to claim 1 , wherein the luminescence peak appears in the near-infrared range including wavelengths between 700 nm and 800 nm.

10. The organic electro-luminescent element according to claim 1 , wherein the luminescent layer comprises a smaller amount of the delayed fluorescent material as compared to an amount of the host material contained in the luminescent layer.

11. The organic electro-luminescent element according to claim 1 , wherein the luminescent layer comprises a smaller amount of the luminescent material as compared to an amount of the host material contained in the luminescent layer.

12. The organic electro-luminescent element according to claim 1 , wherein the luminescent layer comprises an amount of the host material that is 15 wt % to 99.9 wt % with respect to a total amount of the host material, the delayed fluorescent material and the luminescent material contained in the luminescent layer.

13. The organic electro-luminescent element according to claim 1 , wherein the luminescent layer comprises an amount of the delayed fluorescent material that is 5.0 wt % to 50 wt % with respect to a total amount of the host material, the delayed fluorescent material and the luminescent material contained in the luminescent layer.

14. The organic electro-luminescent element according to claim 1 , wherein the luminescent layer comprises an amount of the luminescent material that is 0.1 wt % to 5.0 wt % with respect to a total amount of the host material, the delayed fluorescent material and the luminescent material contained in the luminescent layer.

15. The organic electro-luminescent element according to claim 1 , wherein the luminescent layer comprises an amount of the host material that is 50 wt % to 90 wt %, an amount of the delayed fluorescent material that is 5.0 wt % to 45 wt %, and an amount of the luminescent material that is 0.1 wt % to 5.0 wt %, with respect to a total amount of the host material, the delayed fluorescent material and the luminescent material contained in the luminescent layer.

16. A bioinstrumentation device comprising the organic electro-luminescent element according to claim 1 and a photo detector.

17. An organic electro-luminescent element having a luminescence peak in a near-infrared range, comprising a positive electrode, a negative electrode, and at least one organic layer including a luminescent layer located between the positive electrode and the negative electrode,
wherein the luminescent layer comprises a host material, a delayed fluorescent material, and a luminescent material, and
wherein the delayed fluorescent material and the luminescent material satisfy relationships (1) to (4) shown below:
ΔHOMO+ΔLUMO≤0.6 eV  (1);

|ΔHOMO|≤0.4 eV  (2);

|ΔLUMO|≤0.4 eV  (3); and

| P Abs −P Em |≤30 nm  (4),

wherein “ΔHOMO” represents a value of a highest occupied molecular orbital (HOMO) energy level of the luminescent material minus a HOMO energy level of the delayed fluorescent material, wherein “ΔLUMO” represents a value of a lowest unoccupied molecular orbital (LUMO) energy level of the delayed fluorescent material minus a LUMO energy level of the luminescent material, wherein P Abs represents a maximal value at the longest wavelength side of an absorption spectrum of the luminescent material, and wherein P Em represents a maximal value at the longest wavelength side of an emission spectrum of the delayed fluorescent material.

18. The organic electro-luminescent element according to claim 17 , wherein the host material comprises CBP, wherein the delayed fluorescent material comprises TPA-DCPP, and wherein the luminescent material comprises TPA-ThQ.

19. The organic electro-luminescent element according to claim 17 , wherein the luminescent layer is formed at an approximate mass ratio of CBP:TPA-DCPP:TPA-ThQ=75:24:1.

20. A bioinstrumentation device comprising the organic electro-luminescent element according to claim 17 and a photo detector.

Assignees

• Univ Kyushu Nat Univ Corp
• Hamamatsu Photonics Kk

Inventors

• Adachi Chihaya
• Nakanotani Hajime
• Yamanaka Takahiko
• Hara Shigeo
• Hirohata Toru

Classifications

• H01L51/0034

  Electricity · mapped topic

• H01L51/0059

  Electricity · mapped topic

• A61B5/0059

  using light, e.g. diagnosis by transillumination, diascopy, fluorescence (photoacoustic A61B5/0093; optical measurement of heart rate A61B5/02416; optical measurement of blood flow A61B5/0261; optical measurement of analytes A61B5/1455) · CPC title

• G01N21/6486 Primary

  Measuring fluorescence of biological material, e.g. DNA, RNA, cells (G01N21/6428 takes precedence) · CPC title

• H01L51/5004

  Electricity · mapped topic