A dual host system for OLEDs that contains hole-transporting indolocarbazole and electron-transporting indolocarbazole exhibiting superior performance in the OLEDs is disclosed.

Disclosed are a quantum dot material, a method for patterning a quantum dot film and a quantum dot light emitting device. when preparing a patterned quantum dot film, firstly, a quantum dot film is made by using the quantum dot material with the photolysis group, and a corresponding region of the quantum dot film is irradiated with ultraviolet light under the shielding of a mask template, so that the photolysis group in the corresponding region is photolyzed into the polarity change group, thereby changing the solubility of the quantum dot material in the corresponding region; and subsequently, the quantum dot film is cleaned by using a solvent which can dissolve the quantum dot material with the photolysis group, the quantum dot material in non-irradiated regions is dissolved and removed, and the quantum dot material in the corresponding region is retained to form a pattern of the quantum dot film.

An OLED is disclosed whose emissive layer has a first host and an emitter, where the emitter is a phosphorescent metal complex that is a Pt(II) or Pd(II) complex having a square planar coordinating geometry or has the formula of M(L.sup.1).sub.x(L.sup.2).sub.y(L.sup.3).sub.z, where E.sub.H1T, the T.sub.1 triplet energy of the first host, is higher than E.sub.ET, the T.sub.1 triplet energy of the emitter, where E.sub.ET is at least 2.50 eV, where the LUMO energy of the first host is higher than the HOMO energy of the emitter, where the absolute value of the difference between the HOMO energy of the emitter and the LUMO energy of the first host is ΔE1, where a≤ΔE1−E.sub.ET≤b; and where a≥0.05 eV, and b≤0.60 eV.

A dual host system for OLEDs that contains hole-transporting indolocarbazole and electron-transporting indolocarbazole exhibiting superior performance in the OLEDs is disclosed.

The present specification relates to an organic light emitting device, and a composition for forming an organic material layer.

The present invention relates to compounds suitable for use in electronic devices, and to electronic devices, especially organic electroluminescent devices, comprising these compounds.

An OLED is disclosed whose emissive layer has a first host and an emitter, where the emitter is a phosphorescent metal complex or a delayed fluorescent emitter, where E.sub.H1T, the T.sub.1 triplet energy of the first host, is higher than E.sub.ET, the T.sub.1 triplet energy of the emitter, where E.sub.ET is at least 2.50 eV, where the LUMO energy of the first host is higher than the HOMO energy of the emitter, where the absolute value of the difference between the HOMO energy of the emitter and the LUMO energy of the first host is ΔE1, where a≤ΔE1−E.sub.ET≤b; and where a≥0.05 eV, and b≤0.60 eV.

An organic electroluminescent device having an anode, a cathode, and a light emitting layer between the anode and the cathode, in which the light emitting layer contains a first organic compound, a second organic compound, and a third organic compound that satisfy the following expression (A), the second organic compound is a delayed fluorescent material, and the third organic compound is a light emitting material, is capable of enhancing the light emission efficiency. E.sub.S1(A), E.sub.S1(B) and E.sub.S1(C) represent a lowest, singlet excitation energy level of the first, second and third organic compound, respectively.

E.sub.S1(A)>E.sub.S1(B)>E.sub.S1(C)   (A)

An organic electroluminescent device having an anode, a cathode, and a light emitting layer between the anode and the cathode, in which the light emitting layer contains a first organic compound, a second organic compound, and a third organic compound that satisfy the following expression (A), the second organic compound is a delayed fluorescent material, and the third organic compound is a light emitting material, is capable of enhancing the light emission efficiency. E.sub.S1(A), E.sub.S1(B) and E.sub.S1(C) represent a lowest singlet excitation energy level of the first, second and third organic compound, respectively.
E.sub.S1(A)>E.sub.S1(B)>E.sub.S1(C)  (A)

A dual host system for OLEDs that contains hole-transporting indolocarbazole and electron-transporting indolocarbazole exhibiting superior performance in the OLEDs is disclosed.