Provided are an ultraviolet emitting optical device and an operating method thereof. The ultraviolet emitting optical device includes a substrate, a first encapsulation layer, an active layer and a second encapsulation layer sequentially stacked on the substrate, a first electrode layer between the first encapsulation layer and the active layer, a second electrode layer between the active layer and the second encapsulation layer, and color centers provided in the active layer, wherein the active layer includes hexagonal boron nitride (hBN), wherein the color centers are configured to emit light in an ultraviolet wavelength range.

A full color display includes multiple pixels and has a white point, a direction of emission and a solid angle of emission around the direction of emission characterized by a half-cone angle . Each pixel includes: a sub-pixel including a red LED having a first geometry emitting red light into a range of emission angles, such that a fraction of the power emitted within the solid angle of emission is at least 1.2*(1cos().sup.2); a sub-pixel including a green LED having a second geometry emitting green light into a range of emission angles, such that a fraction of the power emitted within the solid angle of emission is at least 1.2*(1cos().sup.2); and a sub-pixel including a blue LED emitting blue light into a range of emission angles, such that a fraction of the power emitted within the solid angle of emission is at least 1.2*(1cos().sup.2). The LEDs are configured such that, in any direction within the solid angle of emission, white light emitted by the display has a chromaticity difference Duv from the white point of the display which is less than 0.01.

An optoelectronic device including one or a plurality of light-emitting diodes, each light-emitting diode including a three-dimensional semiconductor element, an active area resting on the three-dimensional semiconductor element and a stack of semiconductor layers covering the active area, the active area including a plurality of quantum wells, said stack being in mechanical contact with a plurality of quantum wells.

A display device includes: a substrate including a display region and a non-display region; a plurality of pixels provided in the display region, the plurality of pixels including first to third sub-pixels each having a light emitting region configured to light; a first light emitting element that is provided in each of the first and second sub-pixels and emits first color light, and a second light emitting element that is provided in the third sub-pixel and emits second color light; and a color conversion layer corresponding to each of the first and second sub-pixels, the color conversion layer converting the first color light into light of a set color for each corresponding sub-pixel.

Provided are a solar cell and a light emitting device with low leakage current and low cost, using ZnO fine particles. A p-type ZnO layer (p-type layer) made primarily of p-type ZnO fine particles is formed. P-side electrodes are formed at a plurality of regions on the p-type layer. A thin insulating layer is formed between an n-type layer and the p-type layer. In the insulating layer, openings are formed at regions A each not overlapping the p-side electrodes and being apart from them in a plan view. In the configuration, by thus making the p-side electrodes apart from the regions A, the length of a current path in the p-type layer can be made substantially larger than the layer thickness.

Provided are a solar cell and a light emitting device with low leakage current and low cost, using ZnO fine particles. A p-type ZnO layer (p-type layer) made primarily of p-type ZnO fine particles is formed. P-side electrodes are formed at a plurality of regions on the p-type layer. A thin insulating layer is formed between an n-type layer and the p-type layer. In the insulating layer, openings are formed at regions A each not overlapping the p-side electrodes and being apart from them in a plan view. In the configuration, by thus making the p-side electrodes apart from the regions A, the length of a current path in the p-type layer can be made substantially larger than the layer thickness.

A semiconductor light emitting element includes: a first light emitting part comprising: a first n-side nitride semiconductor layer; a first active layer located on the first n-side nitride semiconductor layer; and a first p-side nitride semiconductor layer located on the first active layer; and a second n-side nitride semiconductor layer. A bonding face of the first light emitting part and a bonding face of the second n-side nitride semiconductor layer are directly bonded. At least one void is present between the bonding face of the first light emitting part and the bonding face of the second n-side nitride semiconductor layer.

A semiconductor light emitting element includes: a first light emitting part comprising: a first n-side nitride semiconductor layer; a first active layer located on the first n-side nitride semiconductor layer; and a first p-side nitride semiconductor layer located on the first active layer; and a second n-side nitride semiconductor layer. A bonding face of the first light emitting part and a bonding face of the second n-side nitride semiconductor layer are directly bonded. At least one void is present between the bonding face of the first light emitting part and the bonding face of the second n-side nitride semiconductor layer.

A crystallographically-oriented metallic film with a two-dimensional crystal layer comprising a substrate, a metal film on the substrate, the two-dimensional crystal layer on the metal film on the substrate, and a tunable microstructure within the two-dimensional crystal layer on the metal film on the substrate, wherein the metal film has crystallographic registry to the two-dimensional crystal layer.

A crystallographically-oriented metallic film with a two-dimensional crystal layer comprising a substrate, a metal film on the substrate, the two-dimensional crystal layer on the metal film on the substrate, and a tunable microstructure within the two-dimensional crystal layer on the metal film on the substrate, wherein the metal film has crystallographic registry to the two-dimensional crystal layer.