An organic light-emitting device (100) comprising an anode (103); a cathode (109); a light-emitting layer (107) between the anode and the cathode; a first hole-transporting layer (105A) comprising a first conjugated hole-transporting polymer between the anode and the light-emitting layer; and a second hole-transporting layer (105B) comprising a second conjugated hole-transporting polymer between the first hole-transporting layer and the light-emitting layer, wherein a lowest excited state energy level of the first hole-transporting polymer is lower than the lowest excited state energy of the second hole-transporting polymer.

A light-emitting element is provided. The light-emitting element includes first and second electrodes and an EL layer therebetween. The EL layer includes a light-emitting layer containing first and second substances. The amount of the first substance is larger than that of the second substance. The second substance emits light. Average transition dipole moments of the second substance are divided into three components in x-, y-, and z-directions which are orthogonal to each other. Components parallel to the first or second electrode are assumed to be the components in the x- and y-directions, and a component perpendicular to the first or second electrode is assumed to be the component in the z-direction. The proportion of the component in the z-direction is represented by a, which is less than or equal to 0.2.

An organic light emitting device including a pair of electrodes and an organic compound layer disposed between the pair of electrodes, wherein the organic compound layer contains, in a weight ratio of 50 wt % or more, an organic compound having a glass transition temperature of 130° C. or more, and the organic compound does not have a moiety represented by formula [1] below, ##STR00001##
where, in formula [1], *'s represent bonding positions.

A display apparatus includes a substrate. A display unit is disposed on the substrate and includes a display region and a non-display region. At least one light-emitting device is disposed in the display region. First and second power supply lines, configured to supply driving power to the at least one light-emitting device, and a pad unit, are disposed in the non-display region. The first power supply line includes a first fan-out wire portion electrically connected to the pad unit, and a first extension portion electrically connected to the first fan-out wire portion. The second power supply line includes a second fan-out wire portion electrically connected to the pad unit, and a second extension portion electrically connected to the second fan-out wire portion. The first extension portion has a width W1 and the second extension portion has a width W2. The width W1 is greater than the width W2.

An organic light emitting device includes a first emitting part on an anode, the first emitting part including a first emission layer and a first hole transport layer a second emitting part on the first emitting part, the second emitting part including a second emission layer and a second hole transport layer; a third emitting part on the second emitting part including a third emission layer and a third hole transport layer; and a cathode on the third emitting part. The third emitting part further includes a fourth emission layer to emit light having a same color as the third emission layer and includes a dopant and a mixed host of at least two hosts, and a fourth hole transport layer provided on the third hole transport layer while in contact with the third emission layer, and has a hole mobility lower than that of the third hole transport layer.

A display device according to one aspect of the disclosure includes an electroluminescence element including a light-emitting layer including quantum dots between a cathode and an anode which are paired, and further includes a platelet layer adjacent to the light-emitting layer and including plate-shaped nanoplatelets.

The invention relates to OLEDs (1) having a substrate (2), a first electrode layer (3), a layer of organic electroluminescence material (4), a second electrode layer (5), a cover layer (6), moisture-absorbing means (9) and a separating foil (10) of resilient material. According to the invention, said foil (10) is positioned between the second electrode layer (5) and the moisture-absorbing means (9). This feature results in a longer mean life-time of the OLED. Advantageously spacer structures (12) (preferably formed as dots) are applied on the separating foil (10) between the foil (10) and the cover (6). This prevents discoloring effects around the rim of the OLED material.

An organic electroluminescent element includes a hole injection layer (HI), a first hole transport layer (HT1), a second hole transport layer (HT2), and a light-emitting layer containing a host compound (H) and a phosphorescence emitting dopant compound (D), which are laminated in this order, between and an anode and a cathode. The phosphorescence emitting dopant compound has a partial structure represented by Formula (1): ##STR00001## The “highest occupied molecular orbital” HOMO of the second hole transport layer satisfies the expression: −5.4<HOMO (HT2)<−4.8; and the relationship of triplet excitation energies (T1) between the phosphorescence emitting dopant compound and a hole transport material contained in the second hole transport layer satisfies the expression: T1 (HT2)−T1 (D)>0.1.

An organic EL display device in an embodiment according to the present invention includes a plurality of first electrodes provided corresponding to each of a plurality of pixels above a first substrate, a bank layer provided above the first substrate between adjacent first electrodes to cover an end part of the first electrode, an organic EL layer provided to cover the plurality of first electrodes and the bank layer, a second electrode provided above the organic EL layer, the organic EL layer includes a first region overlapping the bank layer, and a second region overlapping the plurality of the first electrodes, and a first resistance of the first region is larger than a second resistance of the second region.

The present invention relates to a light-emitting layer B comprising a first emitter compound (a) having a non-exited state S0(a), a first excited singlet state S1(a) and a first excited triplet state T1(a); a second emitter compound (b) having a non-exited state S0(b), a first excited singlet state S1(b) and a first excited triplet state T1(b), wherein the energy level of S1(a) is higher than that of S1(b), the energy level of S1(b) is higher than that of T1(b) and wherein the rate of reverse intersystem crossing from T1(a) to S1(a) is higher than the rate of excition energy transfer from S1(a) to S1(b) and/or the rate of excition energy transfer from T1(a) to T1(b), and/or wherein the energy level of T1(b) is higher than that of T1(a). Further, the present invention also refers to an opto-electronic device comprising such light-emitting layer B and use thereof.