Light-emitting element and display device

A light-emitting element, comprising

• an anode,
• a cathode placed opposite to the anode, and
• a plurality of organic layers placed between the anode and the cathode,
• wherein at least three of the plurality of organic layers each independently contains a compound having a spirobifluorene structure;
• or
• wherein at least two of the plurality of organic layers each contains the compound having the spirobifluorene structure, and the at least two of the plurality of organic layers together contain at least three types of the compound having the spirobifluorene structure,
• wherein the compound having the spirobifluorene structure, when contained in the plurality of organic layers, is selected from a group consisting of compounds represented by general formula I and combinations thereof:
• wherein each of X1, X2, X3 and X4 is independently selected from a group consisting of a hydrogen atom, an electron donating group, and an electron withdrawing group, and at least one of X1, X2, X3 or X4 is independently selected from a group consisting of the electron donating group and the electron withdrawing group;
• and
• wherein n, m, p and q are integers each independently selected from a group consisting of 1, 2, 3 and 4,
• wherein the electron withdrawing group is selected from a group consisting of a halogen atom, nitro, cyano, C1-C40 alkyl unsubstituted or substituted with a substituent, C6-C60 heteroarylamine unsubstituted or substituted with a substituent, C3-C60 heteroaryl unsubstituted or substituted with a substituent, C6-C60 aryl substituted with a substituent, and combinations thereof, wherein the substituent is selected from a group consisting of halogen atom, nitro, and cyano;
• and
• wherein the electron donating group is selected from a group consisting of hydroxyl, C1-C40 alkoxyl unsubstituted or substituted with a substituent, C1-Cao alkyl unsubstituted or substituted with a substituent, C6-C60 aryl unsubstituted or substituted with a substituent, and combinations thereof, wherein the substituent is a hydroxyl group,
• wherein the aryl group of the electron withdrawing group and the aryl group of the electron donating group are each independently selected from a group consisting of phenyl, naphthyl, phenanthryl, fluorenyl, and biphenyl;
• and
• wherein the heteroaryl group is selected from a group consisting of furyl, thienyl, pyrrolyl, thiazolyl, imidazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolyl, quinolinyl, carbazolyl, benzopyrroyl, benzopyridyl, dibenzofuranyl, dibenzothienyl, diphenyltriazinyl, and dipyridyl,
• wherein the plurality of organic layers placed between the anode and the cathode comprises a hole transport layer, a light-emitting layer and an electron transport layer;
• and the plurality of organic layers placed between the anode and the cathode further comprises any one or more of a hole injection layer, an electron injection layer, an electron blocking layer, and a hole blocking layer,
• wherein at least one of the hole injection layer, the hole transport layer and the electron blocking layer independently contains a compound having the spirobifluorene structure satisfying general formula I;
• and
• wherein the light-emitting layer contains a compound having the spirobifluorene structure satisfying general formula I.

A light-emitting element, comprising:

• an anode,
• a cathode placed opposite to the anode, and
• a plurality of organic layers placed between the anode and the cathode,
• wherein at least three of the plurality of organic layers each independently contain a compound having a spirobifluorene structure;
• or
• wherein at least two of the plurality of organic layers each contain the compound having the spirobifluorene structure, and the at least two organic layers together contain at least three types of the compound having the spirobifluorene structure,
• wherein the compound having the spirobifluorene structure, when contained in the plurality of organic layers, is selected from a group consisting of compounds represented by general formula II, and combinations thereof:
• wherein at least one of ring structure L1, ring structure L2, ring structure L3, and ring structure L4 is present in general formula II and is independently an aromatic ring having 6-42 carbon atoms;
• wherein when the ring structure L1 is present in general formula II, the ring structure L1 is fused to C1 and C2, C2 and C3, or C3 and C4;
• wherein when the ring structure L2 is present in general formula II, the ring structure L2 is fused to C5 and C6, C6 and C7, or C7 and C8;
• wherein when the ring structure L3 is present in general formula II, the ring structure L3 is fused to C9 and C10, C10 and C11, or C11 and C11;
• wherein when the ring structure L4 is present in general formula II, the ring structure L4 is fused to C13 and C14, C14 and C15, or C15 and C16;
• wherein R1, R2, R3, R4, R5, R6, R7, and R8 are independently selected from a group consisting of a hydrogen atom, an electron donating group and an electron withdrawing group;
• and
• wherein n, m, p, q, o, r, s, and t are integers each independently selected from a group consisting of 1, 2, 3 and 4.

A light-emitting element, comprising:

• an anode,
• a cathode placed opposite to the anode, and
• a plurality of organic layers placed between the anode and the cathode,
• wherein at least three of the plurality of organic layers each independently contains a compound having a spirobifluorene structure;
• or
• wherein at least two of the plurality of organic layers each contain the compound having the spirobifluorene structure, and the at least two of the plurality of organic layers together contain at least three types of the compound having the spirobifluorene structure,
• wherein the plurality of organic layers placed between the anode and the cathode comprises a hole transport layer, a light-emitting layer and an electron transport layer;
• wherein the plurality of organic layers placed between the anode and the cathode further comprises a hole injection layer, and a hole blocking layer,
• wherein both the hole injection layer and the electron blocking layer contain a compound having a spirobifluorene structure, the compound having a spirobifluorene structure contained in the hole injection layer and the compound having a spirobifluorene structure contained in the electron blocking layer are identical, and a compound having a spirobifluorene structure is present in at least one of the hole injection layer and the electron blocking layer in a doping form.

A display device, comprising a light-emitting element, wherein the light-emitting element comprises:

• an anode,
• a cathode placed opposite to the anode, and
• a plurality of organic layers placed between the anode and the cathode,
• wherein at least three of the plurality of organic layers each independently contain a compound having a spirobifluorene structure;
• or
• wherein at least two of the plurality of organic layers each contain the compound having the spirobifluorene structure, and the at least two organic layers together contain at least three types of the compound having the spirobifluorene structure,
• wherein the compound having the spirobifluorene structure, when contained in the organic layers, is selected from a group consisting of compounds represented by general formula I and combinations thereof:
• wherein X1, X2, X3 and X4 are each independently selected from a group consisting of a hydrogen atom, an electron donating group and an electron withdrawing group, and at least one of X1, X2, X3 and X4 are each independently selected from a group consisting of the electron donating group and the electron withdrawing group;
• and
• wherein n, m, p and q are integers each independently selected from a group consisting of 1, 2, 3 and 4,
• wherein the electron withdrawing group is selected from a group consisting of a halogen atom, nitro, cyano, C1-C40 alkyl unsubstituted or substituted with a substituent, C6-C60 heteroarylamine unsubstituted or substituted with a substituent, C3-C60 heteroaryl unsubstituted or substituted with a substituent, C6-C60 aryl substituted with a substituent, and combinations thereof, wherein the substituent is selected from a group consisting of halogen atom, nitro, and cyano;
• and
• wherein the electron donating group is selected from a group consisting of hydroxyl, C1-C40 alkoxyl unsubstituted or substituted with a substituent, C1-C40 alkyl unsubstituted or substituted with a substituent, C6-C60 aryl unsubstituted or substituted with a substituent, and combinations thereof, wherein the substituent is a hydroxyl group,
• wherein the aryl group of the electron withdrawing group and the aryl group of the electron donating group are each independently selected from a group consisting of phenyl, naphthyl, phenanthryl, fluorenyl, and biphenyl;
• wherein the heteroaryl group is selected from a group consisting of furyl, thienyl, pyrrolyl, thiazolyl, imidazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolyl, quinolinyl, carbazolyl, benzopyrroyl, benzopyridyl, dibenzofuranyl, dibenzothienyl, diphenyltriazinyl, and dipyridyl,
• wherein the plurality of organic layers placed between the anode and the cathode comprises a hole transport layer, a light-emitting layer and an electron transport layer;
• and the plurality of organic layers placed between the anode and the cathode further comprises any one or more of a hole injection layer, an electron injection layer, an electron blocking layer, and a hole blocking layer,
• wherein at least one of the hole injection layer, the hole transport layer and the electron blocking layer independently contains a compound having the spirobifluorene structure satisfying general formula I,
• wherein the light-emitting layer contains a compound having the spirobifluorene structure satisfying general formula I, and
• wherein at least one of the electron injection layer, the electron transport layer and the hole blocking layer independently contains a compound having a spirobifluorene structure satisfying general formula I.