Use of square planar transition metal complexes as dopant

Abstract

The present invention relates to the use of a square planar transition metal complex as dopant, charge injection layer, electrode material or storage material.

Claims

1. A method for p-doping an organic semiconductive matrix material, the method comprising combining an electrical p-dopant with the organic semiconductive matrix material, wherein the electrical p-dopant is a square planar transition metal complex, wherein the square planar transition metal complex comprises one of the following structures: ##STR00003## wherein: M is a transition metal selected from groups 8 to 11 of the periodic system of the elements, X.sub.1, X.sub.2, X.sub.3, and X.sub.4 are independently selected from the group consisting of S, N, and P, wherein N and P are substituted with R.sub.5, and R.sub.5 is independently selected from the group consisting of, substituted or unsubstituted, linear alkyl, branched alkyl, cycloalkyl, aryl, heteroaryl, condensed aromatic rings, donor groups, and acceptor groups, R.sub.1 and R.sub.2 are independently selected from the group consisting of, substituted or unsubstituted, aromatic compounds, heteroaromatic compounds, aliphatic hydrocarbons, cycloaliphatic hydrocarbons, and nitrile, L.sub.1 and L.sub.2 are independently selected from the group consisting of aromatic amine, aromatic phosphine, halogen, pseudohalogen, NCS, SCN, and CN, and wherein the organic semiconductive matrix material is selected from the group consisting of metal phthalocyanine complexes, metal naphthocyanine complexes, metal porphyrine complexes, substituted or unsubstituted, arylated or heteroarylated amines, benzidine derivatives, imidazole derivatives, thiophene derivatives, thiazole derivatives, and dimeric, oligomeric, or polymeric heteroaromates, wherein the selected organic semiconductive matrix material has an oxidation potential, as determined by cyclovoltammetry, of greater than 0 V vs. Fc/Fc.sup.+.

2. The method according to claim 1, wherein M is selected from the group consisting of nickel, copper, palladium, platinum, iron, cobalt, ruthenium, and osmium.

3. The method according to claim 1, wherein R.sub.1 and R.sub.2 are independently selected from the group consisting of substituted phenyl, anisyl, tolyl, 2-pyridyl, methyl, propyl, isopropyl, trifluoromethyl, pentafluoroethyl, and trichloromethyl.

4. An organic semiconductive material comprising at least one organic matrix compound and an electrical p-dopant, wherein the electrical p-dopant is a square planar transition metal complex, wherein the square planar transition metal complex has one of the following structures: ##STR00004## wherein: M is a transition metal selected from groups 8 to 11 of the periodic system of the elements, X.sub.1, X.sub.2, X.sub.3, and X.sub.4 are independently selected from the group consisting of S, N, and P, wherein N and P are substituted with R.sub.5, and R.sub.5 is independently selected from, substituted or unsubstituted, linear alkyl, branched alkyl, cycloalkyl, aryl, heteroaryl, condensed aromatic rings, donor groups, and acceptor groups, R.sub.1 and R.sub.2 are independently selected from the group consisting of, substituted or unsubstituted, aromatic compounds, heteroaromatic compounds, aliphatic hydrocarbons, cycloaliphatic hydrocarbons, and nitrile, L.sub.1 and L.sub.2 are independently selected from the group consisting of aromatic amine, aromatic phosphine, halogen, pseudohalogen, NCS, SCN, and CN, and wherein the organic matrix compound is selected from the group consisting of metal phthalocyanine complexes, metal naphthocyanine complexes, metal porphyrine complexes, substituted or unsubstituted, arylated or heteroarylated amines, benzidine derivatives, imidazole derivatives, thiophene derivatives, thiazole derivatives, and dimeric, oligomeric, or polymeric heteroaromates, wherein the selected organic semiconductive matrix material has an oxidation potential, as determined by cyclovoltammetry, of greater than 0 V vs. Fc/Fc.sup.+.

5. The organic semiconductive material according to claim 4, wherein the molar doping ratio of dopant to matrix molecule or the doping ratio of dopant to monomeric units of a polymeric matrix molecule is between 20:1 and 1:100,000.

6. The method according to claim 3, wherein the substituted phenyl is trifluoromethylphenyl.

7. The organic semiconductive material according to claim 5, wherein the molar doping ratio of dopant to matrix molecule or the doping ratio of dopant to monomeric units of a polymeric matrix molecule is between 10:1 and 1:1,000.

8. The organic semiconductive material according to claim 5, wherein the molar doping ratio of dopant to matrix molecule or the doping ratio of dopant to monomeric units of a polymeric matrix molecule is between 1:1 and 1:100.

Description

EXAMPLES OF APPLICATION

(1) An extremely electron-poor transition metal complex compound is provided in a very high purity.

(2) The presented electron-poor transition metal complex compound is evaporated at the same time with the matrix material. The matrix material can for example be spiro-TTB or α-NPD according to the exemplary embodiment. The p-dopant and the matrix material can be evaporated in such a manner that the layer precipitated on the substrate in a vacuum evaporation system has a doping ratio of p-dopant to matrix material of 1:10.

(3) The layer of the organic semiconductor material, which is in each case doped with the p-dopant is applied on an ITO layer (indium tin oxide) arranged on a glass substrate. After the application of the p-doped organic semiconductor layer a metal cathode is applied, for example, by vapor-depositing a suitable metal on it in order to produce an organic light-emitting diode. It is understood that the organic light-emitting diode can also have a so-called inverted layer construction in which the layer sequence is: Glass substrate metal cathode p-doped organic layer—transparent conductive cover layer (for example, ITO). It is understood that further layers can be provided between the individual mentioned layers depending on the application.

Example 1

(4) The neutral nickel complex bis(cis-1,2-bis[trifluoromethyl]ethylene-1,2-dithiolato)nickel was used for the doping of spiro-TTB as matrix material. Doped layers with a doping ratio of dopant:matrix material of 1:10 were produced by mixed evaporation of matrix and dopant with spiro-TTB. The conductivity was 2×10.sup.−4 S/cm.

Example 2

(5) The neutral nickel complex bis(cis-1,2-bis[trifluoromethyl]ethylene-1,2-dithiolato)nickel was used for the doping of α-NPD as matrix material. Doped layers with a doping ratio of dopant:matrix material of 1:10 were produced by mixed evaporation of matrix and dopant with α-NPD. The conductivity was 2×10.sup.−7 S/cm.

Example 3

(6) The neutral cobalt complex bis(cis-1,2-bis[trifluoromethyl]ethylene-1,2-dithiolato)cobalt was used for the doping of ZnPc as matrix material. Doped layers with a doping ratio of dopant:matrix material of 1:10 were produced by mixed evaporation of matrix and dopant with ZnPc. The conductivity was 2×10.sup.−4 S/cm.

Example 4

(7) The neutral iron complex bis(cis-1,2-bis[trifluoromethyl]ethylene-1,2-dithiolato)iron was used for the doping of ZnPc as matrix material. Doped layers with a doping ratio of dopant:matrix material of 1:10 were produced by mixed evaporation of matrix and dopant with ZnPc. The conductivity was 3×10.sup.−3 S/cm.

Example 5

(8) The neutral nickel complex bis(cis-1,2-bis[trifluoromethyl]ethylene-1,2-dithiolato)nickel was used for the doping of ZnPc as matrix material. Doped layers with a doping ratio of dopant:matrix material of 1:10 were produced by mixed evaporation of matrix and dopant with ZnPc. The conductivity was 4×10.sup.−5 S/cm.

(9) The features of the invention disclosed in the preceding description and in the claims may be essential for the realization of the invention in its various embodiments both individually and in any combination thereof.