Provided is an electroluminescent device. The electroluminescent device includes an anode, a cathode and an organic layer disposed between the anode and the cathode, where the organic layer includes at least a first compound having a structure of H-L-E and a second compound having a general formula of M(L.sub.a).sub.m(L.sub.b).sub.n(L.sub.c).sub.q. The novel material combination consisting of the first compound and the second compound can enable the electroluminescent device to obtain a lower voltage, higher efficiency and an ultra-long lifetime and can provide better device performance. Further provided are a display assembly and a compound combination.

A light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an interlayer between the first electrode and the second electrode and including an emission layer, wherein the interlayer includes an organometallic compound of Formula 1:

##STR00001##

wherein, in Formula 1, the variables are described herein.

Provided is a compound of Formula I

##STR00001##

in which at least one moiety A, moiety B, moiety C, or moiety D is a 6-membered carbocyclic or heterocyclic ring, and at least one R.sup.A, R.sup.B, R.sup.C, or R.sup.D includes a group having Formula II

##STR00002##

where R.sup.X can be silyl, germyl, boryl, nitrile, F, CF.sub.3, cycloalkyl, heterocycloalkyl, or monocyclic heteroaryl. The compounds are useful as emitters in OLEDs providing improved efficiency.

The present disclosure provides for an organic electroluminescent device (OLED) including an anode; a cathode; and an emissive layer, disposed between the anode and the cathode. The emissive layer includes a phosphorescent dopant, a first host, and a second host, wherein the first host transports holes, the second host transports electrons, and the first host is fully or partially deuterated. Consumer products that include the OLED are also provided.

Compounds of Formula I,

##STR00001##

and Formula IIa,

##STR00002##

Formula IIb,

##STR00003##

are provided. In these structures, M is Pt or Pd; each of X.sup.1 to X.sup.6, X.sup.9 to X.sup.12, and Z.sup.1 to Z.sup.3 is C or N; each of L.sup.1, L.sup.2, L.sup.3, and L.sup.4 is a direct bond or a linker; at least three of L.sup.1, L.sup.2, L.sup.3, and L.sup.4 are present; each K.sup.1, K.sup.2, and K.sup.3 is a bond, O, or S; when Z.sup.1 is N, ring A in Formula I is not a pyridine or pyrazole; L.sup.5 is a bond or an organic linker; Y is selected from the group consisting of amino, alkoxy, aryloxy, or SiR.sup.1R.sup.2R.sup.3; when Y is SiR.sup.1R.sup.2R.sup.3, L.sup.2 is not BR. Devices, consumer products, and formulations containing these compounds are also disclosed.

A light-emitting device and an electronic apparatus (including the light-emitting device) are provided. The light-emitting device includes a first compound represented by Formula 1 and a second compound represented by Formula 2:

##STR00001##

wherein detailed descriptions of Formula 1 and Formula 2 are the same as described in the present specification.

A compound comprising a first ligand L.sub.A, where L.sub.A comprises a structure of Formula I,

##STR00001##

is provided. In Formula I, each of X.sup.1, X.sup.2, X.sup.3, and X.sup.4 represents CR, CRR′, NR, or N; Y is selected from a linking group; each of R, R′, R″, R.sup.1, R.sup.1′, R.sup.2, R.sup.2′, R.sup.3, R.sup.3′, R.sup.4, and R.sup.4′ is hydrogen or a substituent; each represents a single bond or a double bond; any two adjacent substituents may be joined or fused to form a ring; two adjacent ones of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are joined together to form a fused 5-membered heterocyclic ring, Ring A, while the remaining two of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 cannot be joined to form an aromatic ring; and Ring A is joined to a metal M by a direct bond. Formulations, OLEDs, and consumer products comprising the compound are also provided.

Novel organic metal complexes containing fused isoquinoline type ligands useful as emitters for near infrared OLED devices are disclosed. Such a compound has a first ligand L.sub.A having the Formula: ##STR00001##

A compound including a first ligand L.sub.A having a structure of Formula I ##STR00001##
is disclosed. The compound is useful a an emitter dopants in OLEDs for enhancing the OLED performance.

Metal-assisted delayed fluorescent emitters employing benzo-imidazo-phenanthridine and analogues for full color displays and lighting applications.