Provided is a light-emitting element including a fluorescence-emitting material with high emission efficiency. The light-emitting element includes a pair of electrodes and an EL layer between the pair of electrodes. The EL layer includes a first organic compound, a second organic compound, and a guest material. The first organic compound has a function of emitting a thermally activated delayed fluorescence at room temperature. The guest material has a function of emitting fluorescence. A HOMO level of the first organic compound higher than or equal to a HOMO level of the second organic compound. A LUMO level of the first organic compound is lower than or equal to a LUMO level of the second organic compound.

An organic electroluminescent device and a display apparatus. The organic electroluminescent device includes a first electrode, a second electrode and at least two organic electroluminescent units located between the first electrode and the second electrode. The at least two organic electroluminescent units are arranged in a stacked manner. The at least two organic electroluminescent units include a first organic electroluminescent unit. The first organic electroluminescent unit includes a first light-emitting layer. The first light-emitting layer contains a first host material, a thermally activated delayed fluorescence sensitizer and a first fluorescent dye.

A novel light-emitting device that is highly convenient, useful, or reliable is provided. The light-emitting device includes a first electrode, a second electrode, a unit, and a first layer. The second electrode includes a region overlapping with the first electrode. The unit includes a region positioned between the first electrode and the second electrode. The unit includes a second layer and a third layer. The second layer includes a region where the third layer is positioned between the second layer and the first electrode. The second layer contains a light-emitting material. The first layer includes a region positioned between the third layer and the first electrode. The first layer contains a material having an acceptor property and a first material. The first layer includes a first region and a second region. The first region includes a region positioned between the second region and the first electrode. The first region contains the material having an acceptor property at a first concentration. The second region contains the material having an acceptor property at a second concentration. Note that the second concentration is higher than zero and lower than the first concentration.

The present disclosure relates to an organic light emitting diode that includes a first electrode; a second electrode facing the first electrode; and a first emitting material layer including a first compound and a second compound and positioned between the first and second electrodes, wherein an overlap ratio between an absorption spectrum of the first compound and an emission spectrum of the second compound is equal to or greater than 35%, and an organic light emitting display including the organic light emitting diode.

A transparent display panel, a method for manufacturing the same, and a transparent display device are provided. the transparent display panel includes a first display substrate including: a first substrate and first pixel units thereon; and a second display substrate including: a second substrate and second pixel units thereon, the second pixel units are in one-to-one correspondence with the first pixel units, each first pixel unit includes a first display unit and a first transparent unit, and each second pixel unit includes a second display unit and a second transparent unit, an orthographic projection of the first display unit on the second substrate substantially coincides with that of the corresponding second display unit on the second substrate, and an orthographic projection of the first transparent unit on the second substrate substantially coincides with that of the corresponding second transparent unit on the second substrate.

A pixel circuit, including: an input sub-circuit, a driving control sub-circuit, a light emission control sub-circuit, a driving sub-circuit, a first light-emitting element and a second light-emitting element, wherein the driving control sub-circuit comprises a capacitor; the input sub-circuit is used for providing a signal of a data signal end to a first node; the driving control sub-circuit adjusts the voltages of the first node, a second node and a third node by means of controlling the voltages at two ends of the capacitor; the light emission control sub-circuit is used for providing a signal of a first power supply signal end to the second node under the signal control of a light emission control signal end; and the driving sub-circuit is used for connecting or disconnecting the connection between the second node and the third node under the signal control of the first node.

A display device comprises a substrate provided with a first subpixel, a second subpixel, a third subpixel, and a fourth subpixel, a first electrode provided on the substrate, an organic light emitting layer arranged on the first electrode, and a second electrode arranged on the organic light emitting layer, wherein the organic light emitting layer includes a first organic light emitting layer and a second organic light emitting layer, the first organic light emitting layer and the second organic light emitting layer are arranged on the first subpixel, the second subpixel, and the fourth subpixel, only the second organic light emitting layer is arranged on the third subpixel, only the first organic light emitting layer emits light on the first subpixel and the second subpixel, only the second organic light emitting layer emits light on the third subpixel, and both of the first organic light emitting layer and the second light emitting layer emit light on the fourth subpixel. Since the organic light emitting layer may emit light in accordance with one-stack voltage even in case of a two-stack structure of the first subpixel and the second subpixel, overall power consumption may be reduced.

A novel functional panel that is highly convenient, useful, or reliable is provided. The functional panel includes a first element, a first reflective film, and an insulating film. The first element includes a first electrode, a second electrode, and a layer containing a light-emitting material; the layer containing a light-emitting material includes a region interposed between the first electrode and the second electrode; the first electrode has a light-transmitting property; and the first electrode has a first thickness. The first electrode is interposed between a region of the first reflective film and the layer containing a light-emitting material, and the first reflective film has a second thickness. The insulating film includes a first opening portion, and the first opening portion overlaps with the first electrode. The insulating film has a first step-like cross-sectional shape, and the first step-like cross-sectional shape surrounds the first opening portion. The first step-like cross-sectional shape includes a first step, and the first step is larger than or equal to a thickness obtained by adding the second thickness to the first thickness.

Increasing transparency of one or more micro-displays. A method includes attaching a transparent cover to at least a portion of a semiconductor wafer. The at least a portion of the semiconductor wafer includes the one or more micro-displays. The one or more micro-displays include one or more active silicon areas. The method further includes, after the transparent cover has been attached to the at least a portion of the semiconductor wafer, removing silicon between one or more of the active silicon areas, causing the one or more micro-displays to have a transparency of at least 50%.

Embodiments of the disclosed subject matter provide a device having a full-color organic light emitting device (OLED) display having a plurality of pixels, with each pixel having a plurality of sub-pixels and where no individual sub-pixel of the plurality of sub-pixels emits white light. The OLED display may be configured to operate with a luminance of at least 1,000 cd/m.sup.2 at the D65 or higher white point, and using not more than a 0.5 mA/cm.sup.2 drive current for a blue sub-pixel of the plurality of sub-pixels based on an overall active area of the full-color OLED display.