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US-20260125406-A1 - ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES

US20260125406A1US 20260125406 A1US20260125406 A1US 20260125406A1US-20260125406-A1

Abstract

Cyclometallated iridium complexes having triphenylene or aza triphenylene and bulky alkyl substitution that can be used as emitters in OLEDs to improve the external quantum efficiency (EQE) and lifetime of OLEDs are disclosed.

Inventors

  • Zhiqiang Ji
  • Alexey Borisovich Dyatkin
  • Jui-Yi Tsai
  • Pierre-Luc T. Boudreault

Assignees

  • UNIVERSAL DISPLAY CORPORATION

Dates

Publication Date
20260507
Application Date
20251231

Claims (20)

  1. 1 . A compound of (L A ) 3-n Ir(L B ) n of Formula I wherein n=0, 1, or 2; wherein Z 1 to Z 16 are each independently C or N; wherein any of Z 13 to Z 16 is C when it forms a bond with Ir, or when it forms a bond with the ring having R 1 ; wherein any chelate ring comprising Ir is a 5-membered ring; wherein R 1 to R 6 each independently represents mono to the maximum allowable substitution, or no substitution; wherein each R 1 to R 6 is independently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein any two substituents may be joined or fused together to form a ring; and at least one R 5 or R 6 is nitrile; wherein at least one of R 1 and R 2 is an alkyl or cycloalkyl group comprising five or more C atoms.
  2. 2 . The compound of claim 1 , wherein each R 1 to R 6 is independently hydrogen, or a substituent selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfanyl, and combinations thereof.
  3. 3 . The compound of claim 1 , wherein at least one R 1 is t-butyl.
  4. 4 . The compound of claim 1 , wherein at least one R 2 comprises a tertiary alkyl group.
  5. 5 . The compound of claim 1 , wherein at least one R 2 is t-butyl.
  6. 6 . The compound of claim 1 , wherein at least one R 3 comprises a tertiary alkyl group.
  7. 7 . The compound of claim 1 , wherein at least one R 3 is t-butyl.
  8. 8 . The compound of claim 1 , wherein at least one R 1 or R 2 comprises a cyclic or polycyclic alkyl.
  9. 9 . The compound of claim 1 , wherein at least one R 1 or R 2 is fully or partially deuterated.
  10. 10 . The compound of claim 1 , wherein Z 1 to Z 16 are each C.
  11. 11 . The compound of claim 1 , wherein at least one of Z 1 to Z 16 is N.
  12. 12 . The compound of claim 1 , wherein at least two of Z 1 to Z 16 are N.
  13. 13 . The compound of claim 1 , wherein L B is selected from the group consisting of:
  14. 14 . An organic light emitting device (OLED) comprising: an anode; a cathode; and an organic layer, disposed between the anode and the cathode, comprising a compound of (L A ) 3-n Ir(L B ) n of Formula I wherein n=0, 1, or 2; wherein Z 1 to Z 16 are each independently C or N; wherein any of Z 13 to Z 16 is C when it forms a bond with Ir, or when it forms a bond with the ring having R 1 ; wherein any chelate ring comprising Ir is a 5-membered ring; wherein R 1 to R 6 each independently represents mono to the maximum allowable substitution, or no substitution; wherein each R 1 to R 6 is independently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein any two substituents may be joined or fused together to form a ring; and at least one R 5 or R 6 is nitrile; wherein at least one of R 1 and R 2 is an alkyl or cycloalkyl group comprising five or more C atoms.
  15. 15 . The OLED of claim 14 , wherein the organic layer is an emissive layer and the compound is an emissive dopant or a non-emissive dopant.
  16. 16 . The OLED of claim 14 , wherein the compound is a sensitizer and the OLED further comprises an acceptor; and wherein the acceptor is selected from the group consisting of fluorescent emitter, delayed fluorescence emitter, and combination thereof.
  17. 17 . The OLED of claim 14 , wherein the organic layer further comprises a host, wherein host comprises at least one chemical group selected from the group consisting of triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene.
  18. 18 . A consumer product comprising an organic light-emitting device (OLED) comprising: an anode; a cathode; and an organic layer, disposed between the anode and the cathode, comprising a compound of (L A ) 3-n Ir(L B ) n of Formula I wherein n=0, 1, or 2; wherein Z 1 to Z 16 are each independently C or N; wherein any of Z 13 to Z 16 is C when it forms a bond with Ir, or when it forms a bond with the ring having R 1 ; wherein any chelate ring comprising Ir is a 5-membered ring; wherein R 1 to R 6 each independently represents mono to the maximum allowable substitution, or no substitution; wherein each R 1 to R 6 is independently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein any two substituents may be joined or fused together to form a ring; and at least one R 5 or R 6 is nitrile; wherein at least one of R 1 and R 2 is an alkyl or cycloalkyl group comprising five or more C atoms.
  19. 19 . A formulation comprising a compound of claim 1 .
  20. 20 . A chemical structure selected from the group consisting of a monomer, a polymer, a macromolecule, and a supramolecule, wherein the chemical structure comprises a compound of claim 1 or a monovalent or polyvalent variant thereof.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 18/328,184, filed Jun. 2, 2023, which is a continuation of U.S. patent application Ser. No. 16/550,376, filed Aug. 26, 2019, which claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 62/731,331, filed Sep. 14, 2018, the entire contents of which are incorporated herein by reference. FIELD The present invention relates to compounds for use as emitters, and devices, such as organic light emitting diodes, including the same. BACKGROUND Opto-electronic devices that make use of organic materials are becoming increasingly desirable for a number of reasons. Many of the materials used to make such devices are relatively inexpensive, so organic opto-electronic devices have the potential for cost advantages over inorganic devices. In addition, the inherent properties of organic materials, such as their flexibility, may make them well suited for particular applications such as fabrication on a flexible substrate. Examples of organic opto-electronic devices include organic light emitting diodes/devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, the organic materials may have performance advantages over conventional materials. For example, the wavelength at which an organic emissive layer emits light may generally be readily tuned with appropriate dopants. OLEDs make use of thin organic films that emit light when voltage is applied across the device. OLEDs are becoming an increasingly interesting technology for use in applications such as flat panel displays, illumination, and backlighting. Several OLED materials and configurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety. One application for phosphorescent emissive molecules is a full color display. Industry standards for such a display call for pixels adapted to emit particular colors, referred to as “saturated” colors. In particular, these standards call for saturated red, green, and blue pixels. Alternatively the OLED can be designed to emit white light. In conventional liquid crystal displays emission from a white backlight is filtered using absorption filters to produce red, green and blue emission. The same technique can also be used with OLEDs. The white OLED can be either a single EML device or a stack structure. Color may be measured using CIE coordinates, which are well known to the art. One example of a green emissive molecule is tris(2-phenylpyridine) iridium, denoted Ir(ppy)3, which has the following structure: In this, and later figures herein, we depict the dative bond from nitrogen to metal (here, Ir) as a straight line. As used herein, the term “organic” includes polymeric materials as well as small molecule organic materials that may be used to fabricate organic opto-electronic devices. “Small molecule” refers to any organic material that is not a polymer, and “small molecules” may actually be quite large. Small molecules may include repeat units in some circumstances. For example, using a long chain alkyl group as a substituent does not remove a molecule from the “small molecule” class. Small molecules may also be incorporated into polymers, for example as a pendent group on a polymer backbone or as a part of the backbone. Small molecules may also serve as the core moiety of a dendrimer, which consists of a series of chemical shells built on the core moiety. The core moiety of a dendrimer may be a fluorescent or phosphorescent small molecule emitter. A dendrimer may be a “small molecule,” and it is believed that all dendrimers currently used in the field of OLEDs are small molecules. As used herein, “top” means furthest away from the substrate, while “bottom” means closest to the substrate. Where a first layer is described as “disposed over” a second layer, the first layer is disposed further away from substrate. There may be other layers between the first and second layer, unless it is specified that the first layer is “in contact with” the second layer. For example, a cathode may be described as “disposed over” an anode, even though there are various organic layers in between. As used herein, “solution processible” means capable of being dissolved, dispersed, or transported in and/or deposited from a liquid medium, either in solution or suspension form. A ligand may be referred to as “photoactive” when it is believed that the ligand directly contributes to the photoactive properties of an emissive material. A ligand may be referred to as “ancillary” when it is believed that the ligand does not contribute to the photoactive properties of an emissive material, although an ancillary ligand may alter the properties of a photoactive ligand. As used herein, and as would be generally understood by one skilled in the art, a first “Highest Occupied Molecular Orbital” (HOMO) or “L