A photoconductive device that generates or detects terahertz radiation includes a semiconductor layer; a structure portion; and an electrode. The semiconductor layer has a thickness no less than a first propagation distance and no greater than a second propagation distance, the first propagation distance being a distance that the surface plasmon wave propagates through the semiconductor layer in a perpendicular direction of an interface between the semiconductor layer and the structure portion until an electric field intensity of the surface plasmon wave becomes 1/e times the electric field intensity of the surface plasmon wave at the interface, the second propagation distance being a distance that a terahertz wave having an optical phonon absorption frequency of the semiconductor layer propagates through the semiconductor layer in the perpendicular direction until an electric field intensity of the terahertz wave becomes 1/e.sup.2 times the electric field intensity of the terahertz wave at the interface.

An LED automobile bulb includes a housing, a holder fixedly connected with the housing and an LED luminous assembly which includes a driver board, wherein: the LED luminous assembly further includes an LED light source arranged above the driver board, and bracket guide wires. One of the wires is electrically connected with the LED light source and used for supporting and positioning the LED light source, at one end; the other end of the bracket guide wire is electrically connected with the driver board. The LED light source includes one or more LED luminous strip packaged by means of COB.

According to example embodiments, an electronic device includes channel layer including a graphene layer electrically contacting a quantum dot layer including a plurality of quantum dots, a first electrode and a second electrode electrically connected to the channel layer, respectively, and a gate electrode configured to control an electric current between the first electrode and the second electrode via the channel layer. A gate insulating layer may be between the gate electrode and the channel layer.

An optical semiconductor device comprises, on a substrate, a fin of diamond-cubic semiconductor material and, at the base of the fin, a slab of that semiconductor material, in a diamond-hexagonal structure, that extends over the full width of the fin, the slab being configured as an optically active material. This semiconductor material can contain silicon. A method for manufacturing the optical semiconductor device comprises annealing the sidewalls of the fin, thereby inducing a stress gradient along the width of the fin.

A quantum dot includes a core-shell structure including a core including a first semiconductor nanocrystal and a shell disposed on the core, and including a material at least two different halogens, and the quantum dot does not include cadmium.

Carbon-based light emitting diodes (LEDs) and techniques for the fabrication thereof are provided. In one aspect, a LED is provided. The LED includes a substrate; an insulator layer on the substrate; a first bottom gate and a second bottom gate embedded in the insulator layer; a gate dielectric on the first bottom gate and the second bottom gate; a carbon material on the gate dielectric over the first bottom gate and the second bottom gate, wherein the carbon material serves as a channel region of the LED; and metal source and drain contacts to the carbon material.

A white light-emitting device of the present invention includes a substrate (101); a diamond semiconductor layer (105) provided on the substrate (101), in which one or a plurality of p-type layers (102), a p-type or n-type layer (103), and one or a plurality of n-type layers (104) are laminated in this order from the substrate (101); a first electrode (106) provided on the layer (102) which injects an electric current; a second electrode (107) provided on the layer (104) which injects an electric current; and a fluorescent member (108) which coats a light emission extraction region of the surface of the diamond semiconductor layer.

The present invention provides a surface mounted light emitting apparatus which has long service life and favorable property for mass production, and a molding used in the surface mounted light emitting apparatus. The surface mounted light emitting apparatus comprises the light emitting device 10 based on GaN which emits blue light, the first resin molding 40 which integrally molds the first lead 20 whereon the light emitting device 10 is mounted and the second lead 30 which is electrically connected to the light emitting device 10, and the second resin molding 50 which contains YAG fluorescent material and covers the light emitting device 10. The first resin molding 40 has the recess 40c comprising the bottom surface 40a and the side surface 40b formed therein, and the second resin molding 50 is placed in the recess 40c. The first resin molding 40 is formed from a thermosetting resin such as epoxy resin by the transfer molding process, and the second resin molding 50 is formed from a thermosetting resin such as silicone resin.

An optical semiconductor device comprises, on a substrate, a fin of diamond-cubic semiconductor material and, at the base of the fin, a slab of that semiconductor material, in a diamond-hexagonal structure, that extends over the full width of the fin, the slab being configured as an optically active material. This semiconductor material can contain silicon. A method for manufacturing the optical semiconductor device comprises annealing the sidewalls of the fin, thereby inducing a stress gradient along the width of the fin.

An optoelectronic device comprising: a first conductive layer, a second conductive layer, an active layer between the first conductive layer and the second conductive layer, wherein the active layer comprises a submicrometer size structure of hexagonal type crystals of an element or alloy of elements selected from the carbon group.