Organic electro-luminescent element and bioinstrumentation device

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 as an assistant dopant;
• and
• a luminescent material as a dopant, wherein each of the delayed fluorescent material and the luminescent material has a N-containing structure with two or three benzene rings bonded to an N atom,
• wherein the N-containing structure of each of the delayed fluorescent material and the luminescent material is selected from formulas (1) to (6):
• and
• each of the delayed fluorescent material and the luminescent material further has a fused ring structure in addition to the N-containing structure, wherein the fused ring structures of the delayed fluorescent material and the luminescent material each having an equivalent set of at least two successive rings selected from the following group:

A bioinstrumentation device comprising:

• a photo detector;
• and
• 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 as an assistant dopant;
• and
• a luminescent material as a dopant, wherein each of the delayed fluorescent material and the luminescent material has a N-containing structure with two or three benzene rings bonded to an N atom,
• wherein the N-containing structure of each of the delayed fluorescent material and the luminescent material is selected from formulas (1) to (6):
• and
• each of the delayed fluorescent material and the luminescent material further has a fused ring structure in addition to the N-containing structure, wherein the fused ring structures of the delayed fluorescent material and the luminescent material each having an equivalent set of at least two successive rings selected from the following group: