A wiring substrate includes ceramic layers and a conductive member. The ceramic layers have an uppermost ceramic layer and a lowermost ceramic layer. The conductive member includes an upper conductive layer disposed on an upper surface of the uppermost ceramic layer, an internal conductive layer interposed between the ceramic layers, and a lower conductive layer disposed on a lower surface of the lowermost ceramic layer. The conductive member defines vias electrically connecting the upper conductive layer, the internal conductive layer, and the lower conductive layer. A total number of a first vias connected to the lower conductive layer is larger than a total number of a second vias connected to the upper conductive layer.

Light-emitting materials are made from a porous light-emitting semiconductor having quantum dots (QDs) disposed within the pores. According to some embodiments, the QDs have diameters that are essentially equal in size to the width of the pores. The QDs are formed in the pores by exposing the porous semiconductor to gaseous QD precursor compounds, which react within the pores to yield QDs. According to certain embodiments, the pore size limits the size of the QDs produced by the gas-phase reactions. The QDs absorb light emitted by the light-emitting semiconductor material and reemit light at a longer wavelength than the absorbed light, thereby down-converting light from the semiconductor material.

An optoelectronic circuit receiving a variable voltage containing alternating ascending and descending phases, which circuit comprises sets of light-emitting diodes mounted in series, a module for each set for comparing the voltage at one of the terminals of the set with at least a first threshold and a control module which is connected to the comparison modules and is suitable, during each ascending phase, for interrupting the flow of a current in each set when said voltage of said set goes above the second threshold or when said voltage of the set which is adjacent to said set and through which current passes goes above the first threshold and is suitable, during each descending phase, for controlling the flow of a current in each set when said voltage of the set which is adjacent to said set and through which current passes goes below the first threshold.

A light emitting device includes one or more light emitting elements, a light transmissive member, and a light reflective member. The one or more light emitting elements each includes an upper surface. The light transmissive member has an upper surface and a lower surface. The light reflective member covers surfaces of the light transmissive member and lateral surfaces of the one or more light emitting elements so as to expose the upper surface of the light transmissive member. The upper surface area of the light transmissive member is smaller than a sum of the upper surface areas of the one or more light emitting elements, and the lower surface area of the light transmissive member is larger than a sum of the upper surface areas of the one or more light emitting elements.

A detection system comprises a semiconductor layer for converting photons or particles into charge carriers and a light emitting layer for generating light from the charge carriers. This can be used for the detection of x-rays or charged particles. The semiconductor layer can include amorphous selenium (a-Se), GaAs, CdZnTe, CdTe or perovskite semiconductors. The light emitting layer might be an organic light emitting diode (OLED), GaAs AlGaAs, InGaAs or perovskite semiconductors. Other possibilities are CdTe or CdZnTe. In addition, useful methods to increase light outcoupling out of the light emission layer are described.

A light-emitting device includes: a light-emitting mesa structure having a first top surface and a peripheral surface connected to the first top surface; a transparent conductive layer that is disposed on the first top surface and that has a second top surface; a first insulating structure that is at least disposed on the peripheral surface and that has a third top surface and an inner tapered surface indented from the third top surface, the inner tapered surface having an acute angle with respect to the second top surface; and a reflective layer that is disposed on the transparent conductive layer and that has a first side surface in contact with the inner tapered surface. A method for manufacturing the light-emitting device is also disclosed.

Method for producing a light emitting semiconductor device comprising a zinc magnesium oxide based layer as active layer, wherein the zinc magnesium oxide based layer comprises an aluminum doped zinc magnesium oxide layer having the nominal composition Zn.sub.1-xMg.sub.xO with 1-350 ppm Al, wherein x is in the range of 0<x0.3. The invention further provides a method for the production of such aluminum doped zinc magnesium oxide, the method comprising heat treating a composition comprising Zn, Mg and Al with a predetermined composition at elevated temperatures, and subsequently annealing the heat treated composition to provide said aluminum doped zinc magnesium oxide.

The present invention provides a film formation method and a film formation apparatus which can fabricate an epitaxial film with +c polarity by a sputtering method. In one embodiment of the present invention, the film formation method of epitaxially growing a semiconductor thin film with a wurtzite structure by the sputtering method on an epitaxial growth substrate heated to a predetermined temperature by a heater includes the following steps. First, the substrate is disposed on a substrate holding portion including the heater to be located at a predetermined distance away from the heater. Then, the epitaxial film of the semiconductor film with the wurtzite structure is formed on the substrate with the impedance of the substrate holding portion being adjusted.

A method for fabricating a Light Emitting Diode (LED) with increased light extraction efficiency, comprising providing a III-Nitride based LED structure comprising a light emitting active layer between a p-type layer and an n-type layer; growing a Zinc Oxide (ZnO) layer epitaxially on the p-type layer by submerging a surface of the p-type layer in a low temperature aqueous solution, wherein the ZnO layer is a transparent current spreading layer; and depositing a p-type contact on the ZnO layer. The increase in efficiency may be more than 93% with very little or no increase in cost.

Provided is a surface light-emitting device comprising a substrate composed of an oriented polycrystalline zinc oxide sintered body in a plate shape, a light emitting functional layer provided on the substrate, and an electrode provided on the light emitting functional layer. According to the present invention, a surface light-emitting device having high luminous efficiency can be inexpensively provided.