By doping an organic compound functioning as an electron donor (hereinafter referred to as donor molecules) into an organic compound layer contacting a cathode, donor levels can be formed between respective LUMO (lowest unoccupied molecular orbital) levels between the cathode and the organic compound layer, and therefore electrons can be injected from the cathode, and transmission of the injected electrons can be performed with good efficiency. Further, there are no problems such as excessive energy loss, deterioration of the organic compound layer itself, and the like accompanying electron movement, and therefore an increase in the electron injecting characteristics and a decrease in the driver voltage can both be achieved without depending on the work function of the cathode material.

Light Emitting Device

A method of fabricating a surface emitting semiconductor laser includes a first step of forming, on a substrate, multiple monitor-use semiconductor layers having stripes radiating from a center of the substrate, and a laser portion that includes semiconductor layers and is located on the periphery of the multiple monitor-use semiconductor layers, a second step of monitoring oxidized conditions on the multiple monitor-use semiconductor layers when a selectively oxidized region is formed in the laser portion, and a third step of controlling oxidization of the selectively oxidized region on the basis of the oxidized conditions thus monitored.

Surface emitting semiconductor laser

A radiation-emitting semiconductor chip includes a carrier and a semiconductor body having a semiconductor layer sequence, wherein an emission region and a protective diode region are formed in the semiconductor body having the semiconductor layer sequence; the semiconductor layer sequence includes an active region that generates radiation, the active region being arranged between a first semiconductor layer and a second semiconductor layer; the first semiconductor layer is arranged on a side of the active region which faces away from the carrier; the emission region has a recess extending through the active region; the first semiconductor layer in the emission region is electrically conductively connected to a first connection layer, wherein the first connection layer extends in the recess from the first semiconductor layer toward the carrier; and the first connection layer in the protective diode region is electrically conductively connected to the second semiconductor layer.

Radiation-emitting semiconductor chip

A thermal management system for reducing or eliminating heat-mediated degradation of LED performance and/or operating life. The system may include a thermal controller arranged to respond to an LED operating condition, and to responsively limit temperature in the LED. The thermal controller in one implementation includes a bypass circuit containing a bypass control element, such as a varistor, Zener diode, or antifuse device, and arranged to divert current from flowing to the LED so that the LED remains in a cool state, e.g., below 75°C. The system may be arranged to (I) at least partially attenuate the power supplied to an LED so as to reduce heat generation in such LED and maintain the LED below a threshold temperature and/or (II) remove heat from the LED to maintain temperature of the LED below a threshold temperature.

Led thermal management system and method

A surface-emitting semiconductor laser device is provided that includes an edge-emitting laser integrated in a semiconductor material with various reflectors and a diffractive lens. The edge-emitting laser has a first section comprising an active MQW region, a second section comprising a passive region and a third section comprising a semi-insulating or un-doped semiconductor bulk layer. This configuration ensures that the injection current will pass through all of the layers of the active region, thereby preventing the occurrence of optical losses due to un-injected areas of the MQW active region. In addition, the inclusion of the passive region ensures that there is no current passing through the interface between the active MQW region and the regrown semiconductor bulk layer. The latter feature improves performance and device reliability.

Surface-emitting semiconductor laser device in which an edge-emitting laser is integrated with a diffractive lens, and a method for making the device

A light-emitting semiconductor component which contains a sequence of semiconductor layers ( 2 ) with an area of p-doped semiconductor layers ( 4 ) and n-doped semiconductor layers ( 3 ) between which a first pn junction ( 5 a, 5 b ) is formed. The pn junction ( 5 a, 5 b ) is subdivided into a light-emitting section ( 7 ) and a protective-diode section ( 8 ) in a lateral direction by means of an insulating section ( 6 ). An n-doped layer ( 9 ), which forms a second pn junction ( 10 ) which acts as a protective diode along with the p-doped area ( 4 ), is applied to the p-doped area ( 4 ) in the area of the protective-diode section ( 8 ), the first pn junction ( 5 b ) in the protective-diode section ( 8 ) having a larger area than the first pn junction ( 5 a ) in the light-emitting section ( 7 ). The protective-diode section ( 8 ) protects the light-emitting semiconductor component from voltage pulses due to electrostatic discharges (ESD).

Marc Phillippens

Papers

Light-Emitting Semiconductor Component Comprising a Protective Diode