38results about How to "Improve hole transport efficiency" patented technology

[Problem] The purpose of the present invention is to provide an organic EL element in which various materials for an organic EL element, which excel in hole injection / transport performance, electron injection / transport performance, electron blocking performance, stability in a thin film state, and durability, are combined so that properties of each of the materials can be effectively demonstrated,thereby achieving (1) high luminous efficiency and power efficiency, (2) low luminescence starting voltage, (3) low practical driving voltage, and (4) particularly long service life. [Solution] An organic EL element having at least a positive electrode, a hole transportation layer, a light emission layer, an electron transportation layer, and a negative electrode in the stated order, wherein theorganic EL element is characterized in that the hole transportation layer includes an arylamine compound represented by general formula (1), and the electron transportation layer includes a compound having a benzoazole ring structure represented by general formula (2). (1) (In the formula, Ar1-Ar5 may be identical to each other or different from each other, and represent a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted fused polycyclic aromatic group. Ar6-Ar8 may be identical to each other or different from each other, and represent a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted fused polycyclic aromatic group. n1 represents 0, 1, or 2. Ar3 and Ar4 may form a ring with a single bond or may form a ring so as to be bonded via a substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom. Ar3 or Ar4 may form a ring with a single bond with a benzene ring to which an Ar3Ar4-N group is bonded, and may form a ring so as to be bonded to each othervia a substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom.) (2) (In the formula, Ar9 and Ar10 may be identical to each other or different from each other, and represent a hydrogen atom, a deuterium atom, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group, or a substituted or unsubstituted alkyl group. Y1 represents a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group, or a substituted or unsubstituted alkyl group. X represents an oxygen atom or a sulfur atom. Z1 and Z2 may be identical to each other or different from each other, and represent a carbon atom or a nitrogen atom).