Abstract: Optical components such as components that emit light and components that detect light may be provided. Optical components that emit light may include displays having arrays of display pixels with respective light-emitting devices such as crystalline semiconductor light-emitting diodes. Optical components that detect light may include image sensors or other components with arrays of photodetectors. The light-emitting devices and photodetectors in the optical components may be overlapped by metalenses such as multielement metalenses. A multielement metalens may have a first metalens element formed from a first layer of nanostructures arranged and an overlapping second metalens element formed from a second layer of nanostructures. Light sources may be provided on a semiconductor and metalens nanostructures may be formed on an opposing surface of the semiconductor.

Abstract: A display panel includes light-emitting devices and pixel circuits. The pixel circuit includes a driving module, a data writing module, and a light-emitting control module. In an embodiment, the pixel circuit comprises first working modes and second working modes. In an embodiment, the data writing module transmits different data voltages to the driving module in at least two of the first working modes. The data writing module transmits a same data voltage to the driving module in any one of the second working modes. Durations taken by the light-emitting control module to control the driving module to transmit a driving current to the light-emitting device in any one of the first working modes are the same. Durations taken by the light-emitting control module to control the driving module to transmit a driving current to the light-emitting device in at least two of the second working modes are different.

Abstract: An organic electroluminescent device and a display apparatus. The organic electroluminescent device includes a light-emitting layer, including a triplet-triplet annihilation type host and a fluorescent dye, where the fluorescent dye has a structure represented by the following Formula (1) or Formula (2). When the fluorescent dye in the light-emitting layer of the organic electroluminescent device combines with the triplet-triplet annihilation type host, the voltage of the device can be reduced, and the luminescence efficiency of the device can be improved.

Abstract: An example tunnel junction ultraviolet (UV) light emitting diode (LED) is described herein. The UV LED can include a mesa structure having at least one of: an n-doped bottom contact region, a p-doped region, and a tunnel junction arranged in contact with the p-doped region. Additionally, a geometry of the mesa structure can be configured to increase respective efficiencies of extracting transverse-electric (TE) polarized light and transverse-magnetic (TM) polarized light from the tunnel junction UV LED. The mesa structure can be configured such that an emitted photon travels less than 10 µm before reaching the inclined sidewall.

Abstract: An organic electroluminescent device and a display apparatus. The organic electroluminescent device includes a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode, where the organic layer includes an emission layer (EML), the EML includes a host material, a thermally activated delayed fluorescence (TADF) sensitizer and a fluorescent dye, and the fluorescent dye is selected from a compound represented by Formula (1).

Abstract: An example tunnel junction ultraviolet (UV) light emitting diode (LED) is described herein. The UV LED can include a mesa structure having at least one of: an n-doped bottom contact region, a p-doped region, and a tunnel junction arranged in contact with the p-doped region. Additionally, a geometry of the mesa structure can be configured to increase respective efficiencies of extracting transverse-electric (TE) polarized light and transverse-magnetic (TM) polarized light from the tunnel junction UV LED. The mesa structure can be configured such that an emitted photon travels less than 10 ?m before reaching the inclined sidewall.

Abstract: Methods and structures are described to facilitate the transfer of device layer coupons with controlled vertical position. In an embodiment, a plurality of device layer coupons is bonded to a receiving substrate with an adhesive layer, where distance between front surfaces of the plurality of device layer coupons and a bulk layer of the receiving substrate is controlled by a plurality of rigid mechanical spacers.

Abstract: Display structures and methods of operation with micro light emitting diode (LED) sidewall gating are described. In an embodiment, a display structure includes a vertically oriented micro LED mounted on a display substrate, in which the micro LED includes a p-n diode with top and bottom electrode sides, and a sidewall gate electrode spanning a sidewall of the p-n diode where the active layer is included. In various embodiments, a bias may be applied to the sidewall gate electrode while driving the micro LED to deplete a minority carrier concentration from the sidewall of the p-n diode.

Abstract: The organic electroluminescent device includes a first electrode, a second electrode and an organic layer located between the first electrode and the second electrode, the organic layer includes a light-emitting layer, the light-emitting layer includes a host material, a thermally activated delayed fluorescence sensitizer and a green fluorescent dye, the green fluorescent dye includes a structure as shown in formula I. A thermally activated sensitized fluorescence technique is used, and the green fluorescent dye of a specific structure in combination with the sensitizer and the host material is used, so as to achieve the effects of narrowing the spectrum of a device and improving the green color purity. The efficiency of the organic electroluminescent device is equivalent to that of a phosphorescent green light device, so that a display panel including the organic electroluminescent device has a large display color gamut area.

Abstract: An example tunnel junction ultraviolet (UV) light emitting diode (LED) is described herein. The UV LED can include a mesa structure having at least one of: an n-doped bottom contact region, a p-doped region, and a tunnel junction arranged in contact with the p-doped region. Additionally, a geometry of the mesa structure can be configured to increase respective efficiencies of extracting transverse-electric (TE) polarized light and transverse-magnetic (TM) polarized light from the tunnel junction UV LED. The mesa structure can be configured such that an emitted photon travels less than 10 ?m before reaching the inclined sidewall.

Abstract: An organic light emitting device and a display apparatus, where the organic light emitting device includes a light-emitting layer, the light-emitting layer includes a host material and a dye, the host material is a triplet-triplet annihilation material, and the dye is the boron-nitrogen material shown in Formula 1. The organic light emitting device has excellent light-emitting efficiency and color purity.

Abstract: An example tunnel junction ultraviolet (UV) light emitting diode (LED) is described herein. The UV LED can include a mesa structure having at least one of: an n-doped bottom contact region, a p-doped region, and a tunnel junction arranged in contact with the p-doped region. Additionally, a geometry of the mesa structure can be configured to increase respective efficiencies of extracting transverse-electric (TE) polarized light and transverse-magnetic (TM) polarized light from the tunnel junction UV LED. The mesa structure can be configured such that an emitted photon travels less than 10 ?m before reaching the inclined sidewall.

Abstract: An example tunnel junction ultraviolet (UV) light emitting diode (LED) is described herein. The UV LED can include a mesa structure having at least one of: an n-doped bottom contact region, a p-doped region, and a tunnel junction arranged in contact with the p-doped region. Additionally, a geometry of the mesa structure can be configured to increase respective efficiencies of extracting transverse-electric (TE) polarized light and transverse-magnetic (TM) polarized light from the tunnel junction UV LED. The mesa structure can be configured such that an emitted photon travels less than 10 ?m before reaching the inclined sidewall.

Abstract: An example ultraviolet (UV) light emitting diode (LED) is described herein. The UV LED can include an n-doped contact region, an active region configured to emit UV light that is arranged between an n-doped region and a p-doped region, and a tunnel junction. The tunnel junction is arranged between the n-doped contact region and the p-doped region. In addition, the tunnel junction can include a heavily p-doped region, a degenerately n-doped region, and a semiconductor region arranged between the heavily p-doped region and the degenerately n-doped region. Each of the heavily p-doped region and the degenerately n-doped region has a gradually varied material energy bandgap to reduce respective depletion barriers within the heavily p-doped region and the degenerately n-doped region.