FIELD OF INVENTION

The present invention relates to the technical field of organic light emitting material, and more particularly, to a hole transporting material using ethylene bisacridine as a core and an organic light emitting diode fabricated by using the hole transporting material.

BACKGROUND

Organic light emitting diodes (OLEDs) have broad application prospects in fields of solid state lighting and flat panel displays, and light emitting materials are main factors affecting light emitting efficiency of organic light emitting diodes. In early days, light emitting guest materials used in organic light emitting diodes were fluorescent materials, having a ratio of singlet exciton and triplet excitons in an organic light emitting diode of 1:3. Therefore, in theory, an internal quantum efficiency (IQE) of the organic light emitting diode can only reach 25%, which limits application of fluorescent electroluminescent devices. Furthermore, due to spin-orbit coupling of heavy atoms, heavy metal complex phosphorescent materials can use both singlet and triplet excitons at a same time to achieve 100% internal quantum efficiency. However, in general, heavy metals used in the heavy metal complex phosphorescent light emitting materials are precious metals such as iridium (Ir) or platinum (Pt), and blue light materials of heavy metal complex phosphorescent light emitting materials still need to be improved.

For currently used top emitting organic light emitting diodes, hole transporting materials are used as a thickest layer, and its energy level and hole mobility have always been in contradiction. However, hole transporting materials with matching energy levels and high hole mobility are currently scarce. Therefore, it is necessary to provide a novel hole transporting material to solve problems existing in the prior art.

SUMMARY

For currently used top emitting organic light emitting diodes, hole transporting materials with matching energy levels and high hole mobility are currently scarce. Therefore, it is necessary to provide a novel hole transporting material to solve the problems existing in the prior art.

In view of this, the present invention provides a hole transporting material using ethylene bisacridine as a core, having the following structural formula (I):


wherein R1 and R2 are selected from



or any combination thereof.

In one embodiment of the present invention, wherein the hole transporting material has the following structural formula:



In one embodiment of the present invention, wherein the hole transporting material is:


and is synthesized by the following synthesis route:



In another embodiment of the present invention, wherein the hole transporting material is:


and is synthesized by the following synthesis route:



In yet another embodiment of the present invention, wherein the hole transporting material is:


and is synthesized by the following synthesis route:



In another embodiment of the present invention, an organic light emitting diode is provided, wherein a material of a hole transporting layer in the organic light emitting diode is the hole transporting material using ethylene bisacridine as a core described above.

The organic light emitting diode further comprises an anode, a cathode, and a light emitting structure located between the anode and the cathode, wherein the light emitting structure comprises the hole transporting material using spirodiacridine as a core described above. The light emitting structure comprises a hole injecting layer, the hole transporting layer, an electron blocking layer, a light emitting layer, and a hole blocking layer, an electron transporting layer, and an electron injecting layer which are sequentially formed.

Advantageous Effects

Compared with the prior art, hole transporting materials using ethylene bisacridine as a core with suitable mobilities under highest occupied molecular orbital (HOMO) energy levels and the lowest unoccupied molecular orbital (LUMO) energy levels are synthesized by the present invention on a structural basis using ethylene bisacridine as the core to incorporate different functional groups, which have the effect of effectively increasing the luminous efficiency of a light emitting structure, while a synthetic route also has improved material synthesis efficiency, which is conducive to the fabrication of organic light emitting diodes with long lifespan and high efficiency.

