117results about How to "Improve hole injection efficiency" patented technology

It is an object to provide an organic light-emitting element having two or more light-emitting layers, wherein degradation of each constituent material for the light-emitting layer is reduced to improve reliability of the element. The present invention provides an organic light-emitting element having a laminated structure with a first mixed light-emitting layer 4 composed of a hole transport material, an electron transport material and a dopant which determines a color of an emitted light, and a second mixed light-emitting layer 5 composed of a hole transport material, an electron transport material and a dopant which determines a color of an emitted light, and also provides an image display device which uses the organic light-emitting element.

An organic EL device comprising a cathode, an anode, and at least one organic compound layer containing an organic compound represented by formula (I):where L0 is any one of o-, p-, and m-phenylene groups which have two, three or four rings and which have a substituent with the proviso that when L0 is a phenylene group having four rings, the phenylene group may have an unsubstituted or substituted aminophenyl group somewhere therein, and at least one of R01, R02, R03 and R04 is any one of the following groups:where R1, R12, R13, R14, R15, R16 and R17 are each a substituted or unsubstituted aryl group, and r1, r2, r3 and r4 are each an integer of 0 to 5 with the proviso that r1+r2+r3+r4>=1.

An organic light-emitting element includes an anode, a functional layer, and a hole injection layer between the anode and the functional layer. The functional layer contains an organic material. The hole injection layer injects holes to the functional layer. The hole injection layer comprises tungsten oxide and includes an occupied energy level that is approximately 1.8 electron volts to approximately 3.6 electron volts lower than a lowest energy level of a valence band of the hole injection layer in terms of binding energy.

An organic electroluminescence type display apparatus of top emission type, in which a thin film transistor (TFT), a flattening film made of organic resin and an organic EL element, in which at least an anode, an electroluminescence layer and a cathode are laminated on the flattening film in this order, are formed in each picture element in a display region on a substrate. The anode is composed of at least two layer film including an aluminum (Al) alloy film containing as a impurity at least one of transition metals of the eighth group of 3d into Al and including a light transmitting conductive oxide film laminated on the Al alloy film.

The present invention discloses a nitride semiconductor light emitting device with improved light efficiency. The nitride semiconductor light emitting device includes a n-type nitride layer and p-type nitride layer, an active layer disposed between the n-type and p-type nitride layers and with a multiple quantum well structure wherein a plurality of quantum well layers and a plurality of quantum barrier layers are stacked alternatively in the active layer, and a superlattice layer between the active layer and the p-type nitride layer with asymmetric structure. Herein, a thickness of a well layers gradually increases from the p-type nitride layer to the active layer and the height of the barrier layers gradually increases from the active layer to the p-type nitride layer and therefore, an injection efficiency of a hole supplied from p-type nitride layer to an active layer is increased.

An organic light-emitting element comprising: an anode; a cathode; banks; a functional layer between the anode and the cathode; and a hole injection layer between the anode and the functional layer. The functional layer includes one or more sublayers including a light-emitting sublayer defined by the banks and that contains an organic material. The hole injection layer comprises tungsten oxide, includes an occupied energy level that is approximately 1.8 electron volts to approximately 3.6 electron volts lower than a lowest energy level of a valence band of the hole injection layer in terms of a binding energy, has a surface facing the functional layer, and has a recessed structure such that a portion of the surface overlapping with the light-emitting sublayer is located closer to the anode than other portions. The recessed structure has a recessed portion whose inner surface is in contact with the functional layer.

A semiconductor light-emitting diode, including: an n-GaN layer, a quantum well layer, an electron blocking layer, and a p-GaN layer, which are sequentially stacked on a substrate. The electron blocking layer includes at least one first AlGaN layer and at least one second AlGaN layer. The first AlGaN layer and the second AlGaN layer are alternately stacked. The adjacent first and second AlGaN layers have different Al component.

The invention discloses an emitting organic laser thin film device equipped with a gold nanoparticle enhanced light pumped surface and an application and a preparation method thereof. The device is based on the gold nanoparticle local surface plasmon resonance effect and scattering effect so that the properties of surface emitting laser can be effectively improved, including enhancement of emitting intensity, reduction of threshold and enhancement of quality factor. The device is characterized in that the device is composed of a glass substrate, gold nanoparticles, a spacing layer and a gain medium. The laser gain medium is composed of doped small organic molecule host and guest materials. The spacing layer and the gain medium are identical in the host materials. The laser structure is used as a color conversion layer to be applied to an organic electro-diode, and an organic dye thin film layer can be excited to emit light in the combined device by using light emitted by the light-emitting layer so that an effective scheme can be provided for realizing a simple structure electrically pumped organic laser device. The structure is prepared by a vacuum vapor plating method so as to be easy and fast.

To realize an organic EL device having an excellent hole injection efficiency, improved luminous efficiency, low operating voltage, and low cost, the invention provides an organic EL device comprising a hole injecting electrode, an electron injecting electrode, and at least one organic layer between the electrodes, at least one of the organic layer having a light emitting function. The device further has a high resistance inorganic hole injecting layer between the hole injecting electrode and the organic layer. The high resistance inorganic hole injecting layer is capable of blocking electrons and has conduction paths for carrying holes.

The present invention provides an AlGa-based semiconductor ultraviolet device for improving luminous efficiency and a preparation method thereof, and relates to the technical field of semiconductors.The epitaxial structure of the device comprises a substrate, an AlN buffer layer, an n-type AlGaN layer, an AlxGa1-xN/AlyGa1-yN luminescence active region, the last one AlGaN quantum barrier layer, ap-type AlGaN electron blocking layer, a p-type AlGaN layer and a contact layer, wherein 0.01<=x and y<=1. The luminescence active region comprises a plurality of quantum well layers and a plurality ofquantum barrier layers, the quantum well layers and the quantum barrier layers are alternately arranged, and the last one AlGaN quantum barrier layer is an aluminium ingredient gradient layer. The last one AlGaN quantum barrier layer of aluminium ingredient gradient is introduced in the ultraviolet device to optimize the energy band structure of the device, effectively improve the electron restriction effect and enhance the cavity injection efficiency so as to improve the quantum efficiency and the luminescence efficiency of the semiconductor ultraviolet device.

The invention discloses a semiconductor white light light-emitting diode. The semiconductor white light light-emitting diode is characterized in that V-pits comprise first V-pits and second V-pits; the first V-pits comprise non-doped ZnO quantum dots and CdS<y>Se<1-y>/ZnO core-shell structured nanometer columns to give out red light; the second V-pits comprise non-doped ZnO quantum dots and ZnS<z>Se<1-z>/ZnO core-shell structured nanometer columns to give out green light; multiple quantum wells between the first V-pits and the second V-pits give out blue light; and therefore, the white light light-emitting diode mixed by the red light, the green light and the blue light is formed.

Disclosed in one embodiment is a light-emitting device comprising: a first conductive semiconductor layer; an active layer arranged on the first conductive semiconductor layer, and including a plurality of first recesses; an EBL arranged on the active layer, and including a plurality of second recesses arranged on the first recesses; and a second conductive semiconductor layer arranged on the EBL, wherein the ratio of a first area doping concentration and a second recess doping concentration is from 1:0.8 to 1:1, the active layer emits first light and second light, the first light has a peak in a wavelength of 450 nm to 499 nm, and the second light has a peak in a wavelength of 500 nm to 550 nm.

The invention belongs to the technical field of power semiconductors, and specifically relates to an SOI LIGBT with a controllable collector trough. Compared with a conventional structure, the LIGBT mainly introduces a controllable collector trough structure to a collector end and introduces a plurality of trough grid structures to the collector. During the forwarding conduction, the bias voltage of a trough collector relative to the collector is negative, and a side wall of the collector trough forms a high-density P-type reflection layer so as to increase the hole implantation. The segmented trough grid structures serve as the blocking layers of hole extraction. Therefore, the increase of the hole/electron concentration in a drift region facilitates the obtaining of a lower forwarding conduction voltage drop. Meanwhile, because an N+ collector region is located on the upper surface of a P+ collector region and does not make contact with an N-type drift region, a new device does not has a voltage turning-back effect. The beneficial effects of the invention are that the LIGBT, compared with a conventional short-circuit anode-LIGBT structure, is higher in switching-off speed and lower in forwarding conduction voltage drop, and does not have the voltage turning-back effect.

An organic electroluminescent device including a first electrode layer, a second electrode layer, a light emitting layer and a hole injection layer is provided. The light emitting layer is disposed between the first electrode layer and the second electrode layer. The hole injection layer is disposed between the first electrode layer and the light emitting layer, wherein the hole injection layer includes a first material layer and a second material layer. The second material layer is disposed on the first material layer and includes a main material and a doping material, wherein the doping material of the second material layer and a material of the first material layer are substantially the same.

The invention discloses a light emitting diode with an electron blocking layer in a resonant tunneling structure. The light emitting diode comprises a substrate, an n-type nitride layer, a multiple quantum well layer, the electron blocking layer, a p-type nitride layer and a p-type nitride ohmic contact layer, an n-type electrode which is arranged on the n-type nitride layer, and a p-type electrode which is arranged on the p-type nitride layer, wherein the substrate, the n-type nitride layer, the multiple quantum well layer, the electron blocking layer, the p-type nitride layer and the p-type nitride ohmic contact layer are arranged in order from the bottom up. The electron blocking layer is composed of a p-type doped nitride barrier layer, a non-doped nitride potential well layer, and a non-doped barrier layer which increases the hole transmittance through a resonance tunneling effect, wherein the p-type doped nitride barrier layer, the non-doped nitride potential well layer and the non-doped barrier layer are arranged in order from bottom to top. The light emitting diode provided by the invention has the advantages that electrons are effectively prevented from passing through an active region into a p-type region, which increases the injection efficiency of a hole into the active region through the electron blocking layer; a good electronic blocking effect is realized through a simple growth mode and less layer structures; and the hole injection efficiency significantly higher than a traditional electronic blocking layer structure is acquired.

This invention generally relates to an optoelectronic device and a method of fabricating such a device, and more particularly to an optoelectronic device comprising an anode layer, a semiconductive layer provided over the anode layer, and a cathode layer provided over the semiconductive layer, the anode layer comprising a plurality of electrically conductive tracks connected together and spaced apart from one another with gaps therebetween, the device further comprising a first and one or more further hole injection layers provided between the anode layer and the semiconductive layer and extending across said gaps, wherein the first hole injection layer has a conductivity greater than the conductivity of the one or more further hole injection layers.

The invention provides an LED epitaxial structure and a making method thereof. The LED epitaxial structure sequentially comprises, from bottom to top, a substrate, a first conductivity type semiconductor layer, a superlattice, a multiple-quantum well layer with V-shaped pits, a hole injection layer, and a second conductivity type semiconductor layer, and is characterized in that the hole injection layer is shaped as a double-hexagonal pyramid, fills the V-shaped pits, and is embedded into the second conductivity type semiconductor layer.

The invention relates to an LED epitaxial structure based on an h-BN tunnel junction as a hole injection layer. The invention is characterized in that the epitaxial structure comprises a substrate, an n-type semiconductor material layer, a multi-quantum well layer, a p-type electronic blocking layer, a p-type semiconductor material layer, a p-type heavily doped semiconductor material layer, an h-BN layer and an n-type heavily doped semiconductor material layer, the relative dielectric constant of the n-BN layer is 3-5.1, the relative dielectric constant is less than the relative dielectric constant of the p-type heavily doped semiconductor material layer and the n-type heavily doped semiconductor material layer, the thickness of the h-BN layer is 1nm-5nm; and the p-type heavily doped semiconductor material layer, the h-BN layer and the n-type heavily doped semiconductor material layer constitute a tunnel junction together. The LED epitaxial structure has a tunnel junction structure capable of improving the hole injection efficiency of an LED device, thereby increasing the tunneling probability of carriers, improving the current expansion effect, and significantly improving the quantum efficiency and light output power in the LED.