Abstract: An organic light-emitting diode (OLED) display may have an array of organic light-emitting diode pixels that each have OLED layers interposed between a cathode and an anode. Voltage may be applied to the anode of each pixel to control the magnitude of emitted light. The conductivity of the OLED layers may allow leakage current to pass between neighboring anodes in the display. To reduce leakage current and the accompanying cross-talk in a display, a cutting structure may disrupt continuity of the OLED layers. The cutting structure may have two undercuts to disrupt continuity of at least some of the OLED layers. The cutting structure may include a conductive portion that provides a cathode voltage to a cathode layer for the OLED pixels.

Abstract: An electronic device may have a display such as an organic light-emitting diode (OLED) display. The OLED display may have an array of OLED pixels that each have OLED layers interposed between a cathode and an anode. The pixels may be microcavity OLED pixels having optical cavities. The optical cavities may be defined by a partially transparent cathode layer and a reflective anode structure. The distance between the partially transparent cathode layer and the reflective anode structure for a pixel may be selected such that light at the wavelength emitted by the pixel forms a standing wave between the anode and the cathode. The standing wave may have only one anti-node and the emissive layer for the pixel may be aligned with that one anti-node. To mitigate short circuits, a roughness reduction layer and/or short-circuit-reducing layer having a high sheet resistance may be formed between the anode the OLED layers.

Abstract: An organic light emitting device having an exciton generation layer that contains a compound having a difference between the lowest excited singlet energy level ES1 and the lowest excited triplet energy level ET1 thereof of 0.3 eV or less, or an exciplex to emit delayed fluorescence, and a light emitting layer that contains a light emitting material has a high efficiency and a long lifetime.

Abstract: An organic light-emitting device having an organic mixed layer that contains a first organic compound and a second organic compound and a third organic compound satisfying ES1(A)>ES1(B)>ES1(C). ES1(A), ES1(B) and ES1(C) each represent a lowest excited singlet energy level of the first organic compound, the second organic compound and the third organic compound, respectively. The second organic compound and the third organic compound are delayed fluorescent materials. The invention provides an organic light-emitting device having a long lifetime and a high light emission efficiency.

Abstract: An organic electroluminescent device having a structure of at least an anode 2, a light-emitting layer 3, an electron transporting layer 5 and a cathode 6 layered in that order, and having a charge trap concentration reducing layer 4 in the interface between the light-emitting layer 3 and the electron transporting layer 5 can suppress performance deterioration with time in driving to prolong the lifetime thereof.

Abstract: An organic light emitting device having an exciton generation layer that contains a compound having a difference between the lowest excited singlet energy level ES1 and the lowest excited triplet energy level ET1 thereof of 0.3 eV or less, or an exciplex to emit delayed fluorescence, and a light emitting layer that contains a light emitting material has a high efficiency and a long lifetime.

Abstract: An organic electroluminescent device having an anode, a cathode, and a light-emitting layer between the anode and the cathode, wherein the light-emitting layer contains at least a first organic compound, a second organic compound and a third organic compound satisfying the following formula (A), the second organic compound is a delayed fluorescent material, and the third organic compound is a light-emitting material, has a high light emission efficiency. Formula (A): ES1(A)>ES1(B)>ES1(C) wherein ES1(A), ES1(B) and ES1(C) each represent a lowest excited singlet energy level of the first organic compound, the second organic compound and the third organic compound, respectively.

Abstract: A compound represented by the following general formula (1) is useful as a charge transport material and others in organic light emitting materials. Ar1 to Ar3 each represents an aryl group or a heteroaryl group and at least one of Ar1 to Ar3 contains a skeleton represented by the following general formula (2). In the general formula (2), X represents O or S. R1 to R8 each represent a hydrogen atom, a substituent or a bonding position.

Abstract: An organic electroluminescent device having a structure of at least an anode 2, a light-emitting layer 3 and a cathode 4 layered in that order, wherein the light-emitting layer 3 contains a first host material, a second host material and a light-emitting material of a dopant, and both the first host material and the second host material have a lowest excited triplet energy level higher than the lowest excited triplet energy level of the light-emitting material. The device is protected from performance deterioration with time in driving and has a long lifetime.

Abstract: An organic electroluminescent device having a structure of at least an anode 2, a light-emitting layer 3, an electron transporting layer 5 and a cathode 6 layered in that order, and having a charge trap concentration reducing layer 4 in the interface between the light-emitting layer 3 and the electron transporting layer 5 can suppress performance deterioration with time in driving to prolong the lifetime thereof.