A light-emitting element includes a first electrode, a second electrode, and a functional layer provided between the first electrode and the second electrode. Moreover, the light-emitting element includes: a third electrode provided to the functional layer through a first insulating film; a fourth electrode provided to the functional layer through a second insulating film; a stress applying unit made of a piezoelectric material, and applying stress to the functional layer in response to application of a voltage from the third electrode and the fourth electrode; a power supply connected to the third electrode and the fourth electrode; a detecting unit detecting a condition of the functional layer; a storage unit storing predetermined threshold value information; and a control unit controlling the power supply in accordance with a result of the detection obtained from the detecting unit and the predetermined threshold information stored in the storage unit.

A light-emitting element includes a first electrode, a second electrode, and a functional layer provided between the first electrode and the second electrode. Moreover, the light-emitting element includes: a third electrode provided to the functional layer through a first insulating film; a fourth electrode provided to the functional layer through a second insulating film; a stress applying unit made of a piezoelectric material, and applying stress to the functional layer in response to application of a voltage from the third electrode and the fourth electrode; a power supply connected to the third electrode and the fourth electrode; a detecting unit detecting a condition of the functional layer; a storage unit storing predetermined threshold value information; and a control unit controlling the power supply in accordance with a result of the detection obtained from the detecting unit and the predetermined threshold information stored in the storage unit.

A top-emission type organic electroluminescent (EL) element and a top-emission type organic EL device are provided. The top-emission type organic EL element includes a first electrode, an organic functional layer disposed on the first electrode, and a second electrode disposed on a side of the organic functional layer facing away from the first electrode. The second electrode includes a work-function adjustment layer and a transparent metal oxide layer. The work-function adjustment layer is disposed on the side of the organic functional layer facing away from the first electrode, and the transparent metal oxide layer is disposed on a side of the work-function adjustment layer facing away from the organic functional layer. The top-emission type organic EL element and the top-emission type organic EL device can improve the luminous efficiency and prolong the service life.

A light-emitting device includes a second electrode that includes: a first layer including a first metal having a work function with an absolute value of 5.2 eV or less and a second metal having an electrical conductivity of 1×10.sup.7 S/m or more; and a second layer consisting of the second metal having the electrical conductivity of 1×10.sup.7 S/m or more. The first metal and the second metal are different from each other, a thickness of the first layer is from 1 Å to 30 Å, and a thickness of the second layer is from 10 Å to 110 Å.

The disclosure provides a display substrate and a manufacturing method thereof, a display panel and a display apparatus. The display substrate includes a substrate and an electroluminescent layer on the substrate. The display substrate further includes a first reflective electrode layer, a buffer layer and a second reflective electrode layer sequentially formed on a side of the electroluminescent layer distal to the substrate. The buffer layer is provided with a first hollow region, the second reflective electrode layer is provided with a second hollow region, an overlapping region between the first hollow region and the second hollow region is configured to transmit light emitted by the electroluminescent layer. The present disclosure can detect the light-emitting brightness of each sub-pixel in the organic electroluminescent layer in real time to improve light-emitting efficiency.

The disclosure provides a display substrate and a manufacturing method thereof, a display panel and a display apparatus. The display substrate includes a substrate and an electroluminescent layer on the substrate. The display substrate further includes a first reflective electrode layer, a buffer layer and a second reflective electrode layer sequentially formed on a side of the electroluminescent layer distal to the substrate. The buffer layer is provided with a first hollow region, the second reflective electrode layer is provided with a second hollow region, an overlapping region between the first hollow region and the second hollow region is configured to transmit light emitted by the electroluminescent layer. The present disclosure can detect the light-emitting brightness of each sub-pixel in the organic electroluminescent layer in real time to improve light-emitting efficiency.

An organic EL element includes a pixel electrode, a light emitting function layer that is formed on the pixel electrode, an electron injection layer formed on the light emitting function layer, and a counter electrode that is formed on the electron injection layer and that has semi-transmissive reflectivity, in which the counter electrode contains a reductive material that reduces material of the electron injection layer and Ag with atomic ratio of 75% or more, and an adsorption layer is formed on the counter electrode.

An organic EL element includes a pixel electrode, a light emitting function layer that is formed on the pixel electrode, an electron injection layer formed on the light emitting function layer, and a counter electrode that is formed on the electron injection layer and that has semi-transmissive reflectivity, in which the counter electrode contains a reductive material that reduces material of the electron injection layer and Ag with atomic ratio of 75% or more, and an adsorption layer is formed on the counter electrode.

Organic light emitting materials and devices comprising phosphorescent metal complexes comprising ligands comprising aryl or heteroaryl groups substituted at both ortho positions are described. An organic light emitting device, comprising: an anode, a hole transport layer; an organic emissive layer comprising an emissive layer host and an emissive dopant; an electron impeding layer, and electron transport layer, and a cathode disposed, in that order, over a substrate.

Organic light emitting materials and devices comprising phosphorescent metal complexes comprising ligands comprising aryl or heteroaryl groups substituted at both ortho positions are described. An organic light emitting device, comprising: an anode, a hole transport layer; an organic emissive layer comprising an emissive layer host and an emissive dopant; an electron impeding layer; and electron transport layer; and a cathode disposed, in that order, over a substrate.