CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims priority from and the benefit under 35 U.S.C. 119(a) of Korean Patent Application No. 10-2015-0073550, filed on May 27, 2015, which is hereby incorporated by reference for all purposes as if fully set forth herein. Further, this application claims the benefit of priority in countries other than U.S.A, which is hereby incorporated by reference herein.

BACKGROUND

Technical Field

The present invention relates to compounds for organic electric elements, organic electric elements comprising the same, and electronic devices thereof.

Background Art

In general, an organic light emitting phenomenon refers to a phenomenon in which electric energy is converted into light energy of an organic material. An organic electric element utilizing the organic light emitting phenomenon usually has a structure including an anode, a cathode, and an organic material layer interposed therebetween. In many cases, the organic material layer has a multi-layered structure having respectively different materials in order to improve efficiency and stability of an organic electric element, and for example, may include a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, or the like.

Materials used as an organic material layer in an organic electric element may be classified into a light emitting material and a charge transport material, for example, a hole injection material, a hole transport material, an electron transport material, an electron injection material, and the like according to its function.

Currently, the power consumption is required more and more as size of display becomes larger and larger in the portable display market. Therefore, the power consumption is a very important factor in the portable display with a limited power source of the battery, and efficiency and life span issue also must be solved.

Efficiency, life span, driving voltage, and the like are correlated with each other. For example, if efficiency is increased, then driving voltage is relatively lowered, and the crystallization of an organic material due to Joule heating generated during operation is reduced as driving voltage is lowered, as a result of which life span shows a tendency to increase. However, efficiency cannot be maximized only by simply improving the organic material layer. This is because long life span and high efficiency can be simultaneously achieved when an optimal combination of energy levels and T1 values, inherent material properties (mobility, interfacial properties, etc.), and the like among the respective layers included in the organic material layer is given.

Further, recently, in order to solve the emission problem in a hole transport layer and driving voltage of an organic electric element, it is needed to form an emission-auxiliary layer (multilayered hole transport layer) between the hole transport layer and a light emitting layer, and it is time to develop different emission-auxiliary layers according to respective light emitting layers.

In general, an electron which is transferred from an electron transport layer to a light emitting layer and a hole which is transferred from a hole transport layer to the light emitting layer are recombined to form an exciton in a light emitting layer.

However, the material used for the hole transport layer has a low HOMO value and therefore has a low T1 value. As a result, the exciton generated in the light emitting layer is transferred to the hole transport layer, resulting in a charge unbalance in the light emitting layer and light is emitted at the interface of the hole transport layer.

When light is emitted at the interface of the hole transport layer, color purity and efficiency of the organic electronic device are lowered and the lifetime is shortened. Therefore, it is strongly desired to develop a light-emitting auxiliary layer material having a HOMO energy level between the HOMO energy level of the hole transport layer and the HOMO energy level of the light emitting layer, a high T1 value and a hole mobility within a proper driving voltage range (within a blue device driving voltage range of a full device).

However, this cannot be achieved simply by the structural properties of the core of an emission-auxiliary layer material. High efficiency and long lifespan of device can be achieved when the characteristics of the core and the sub-substituent and the proper combination of the emission-auxiliary layer and the hole transport layer and of the emission-auxiliary layer and the light-emitting layer are met.

On the other hand, it is required to develop a hole injection/transport layer material that retards penetration/diffusion of metal oxides from an anode electrode (ITO) into an organic layer, which is one cause for the shortened life span of an organic electric element, and has stability against Joule heat generated during the operation of an organic electric element, that is, a high glass transition temperature. Also, it has been reported that a low glass transition temperature of a hole transport layer material has a great effect on the life span of an organic electric element because the uniformity of a thin film surface collapses during the operation of the element. In addition, deposition is a main method of forming an OLED, and thus there is an actual need to develop a material that is durable to such a deposition method, that is, a highly heat-resistant material.

That is, it should be preceded that the materials consisting an organic material layer of the element, for example, a hole injection material, a hole transport material, a light emitting material, an electron transport material, an electron injection material, or the like, are supported by a stable and efficient material. Particularly, it is strongly required to develop materials of the emission-auxiliary layer and the hole transport layer.

SUMMARY

In order to solve one or more of the above-mentioned problems in prior art, an aspect of the present invention is to provide a compound having efficient electron blocking ability and hole transport ability and allowing to improve luminous efficiency, to lower a driving voltage, to have a high heat-resistance, and to improve color purity and lifetime of the element, an organic electric element comprising the same, and an electronic device thereof.

In accordance with an aspect of the present invention, the compound represented by the following formula is provided. The following formula represents the compound having dibenzofuran fused with an aromatic ring and bonded to the tertiary amine



In another aspect of the present invention, organic electric elements comprising the compound represented by the formula above and electronic devices including the organic electric element are provided.

According to the embodiments of the present invention, by using a specific compound having a substituent which enhances the planity of a molecule as a material of the organic electric device, hole transport ability and thermal stability are improved, and the HOMO energy level and the high T1 value are easy to balance the charge in the light emitting layer. As a result, luminous efficiency, heat-resistance, and lifetime of the organic electric elements can be improved and a driving voltage of the organic electric elements can be lowered.

