32results about How to "Low roll-off" patented technology

Disclosed is a method for polishing a silicon wafer, wherein a surface to be polished of a silicon wafer is rough polished, while supplying a polishing liquid, which is obtained by adding a water-soluble polymer to an aqueous alkaline solution that contains no free abrasive grains, to a polishing cloth. Consequently, the surface to be polished can be polished at high polishing rate and the flatness of the edge portion including roll-off and roll-up can be controlled.

The invention belongs to the technical field of display, and particularly relates to an organic electroluminescent device, in particular to an efficient fluorescent device. The organic electroluminescent device includes a thermally activated delayed fluorescent material, a first host material, and a fluorescent dye. A hole transport layer can form an interfacial exciplex with the first host material and further sensitize the fluorescent dye by using the thermally activated delayed fluorescent material as a sensitizer. According to the thermal activation delayed fluorescence (TSF) organic electroluminescent device prepared by the method, the external quantum efficiency exceeds the external quantum efficiency of a traditional fluorescent device by about 5%, the luminous efficiency of a fluorescent OLED device is greatly improved, and meanwhile, theorganic electroluminescent device has the advantages of low turn-on voltage, low roll-off and the like.

A polishing composition containing a silica, an acid, a surfactant, and water, wherein (a) the acid has solubility in water at 25° C. of 1 g or more per 100 g of an aqueous saturated solution; (b) the surfactant is a sulfonic acid represented by the formula (1) or (2), or a salt thereof; and (c) the polishing composition has a pH of a specified range; and a polishing process of a substrate using the polishing composition are provided. The polishing composition is suitably used, for example in polishing a substrate for disk recording media such as magnetic disks, optical disks and opto-magnetic disks.

The present invention relates to a silicon-containing organic compound and an application thereof. The silicon-containing organic compound comprises one or more silicon atoms, and has a ΔE (S1−T1)≤0.20 eV, allowing the compound to exhibit a property of thermally activated delayed fluorescence (TADF). The silicon-containing organic compound can be used as a TADF light emitting material. Combination thereof with a suitable host material will improve a luminous efficiency and a lifespan of an electroluminescent device. The silicon-containing organic compound thereby provides a low cost, high performance, long life span, and low roll-off light-emitting device.

The disclosure relates to preparation of silicon on insulator structures with reduced unbonded regions and to methods for producing such wafers by minimizing the roll-off amount (ROA) of the handle and donor wafers. Methods for polishing wafers are also provided.

The current invention relates to novel platinum(II) based organometallic materials. These materials show high emission quantum efficiencies and low self-quenching constant. Also provided are high efficiency, green to orange emitting organic light-emitting diode (OLED) that are fabricated using platinum(II) based organometallic materials as the light-emitting material. The organometallic materials of the invention are soluble in common solvents; therefore, solution process methods such as spin coating and printing can be used for device fabrication. The devices fabricated from these materials show low efficiency roll-off.

Disclosed is a method for polishing a silicon wafer, wherein a surface to be polished of a silicon wafer is rough polished, while supplying a polishing liquid, which is obtained by adding a water-soluble polymer to an aqueous alkaline solution that contains no free abrasive grains, to a polishing cloth. Consequently, the surface to be polished can be polished at high polishing rate and the flatness of the edge portion including roll-off and roll-up can be controlled.

The present invention relates to a tetradentate platinum (II) complex material based on oxazole, thiazole or imidazole and its application. The complex has the O-N-C-N configuration, the structure isas shown in formula (1), wherein A1-A4 is a substituted or unsubstituted five-membered ring, a six-membered ring and a fused ring structure; X is oxygen, sulfur or substituted nitrogen (-NR0), R0 is one or more R-substituted or unsubstituted C1-C8 alkyl, C5-C20 aryl or heteroaryl, R is halogen, C1-C4 alkyl, diphenylamino, carbazolyl, fluorenyl. The complex can be used as a phosphorescent dopant inthe field of OLED. Organometallic complexes with high fluorescence quantum efficiency, good thermal stability and low quenching constant can be used to fabricate yellow-green OLED devices with high luminescence efficiency and low roll-off.

A polishing composition comprising an abrasive, water and an organic acid or a salt thereof, wherein the composition has a specified viscosity of from 1.0 to 2.0 mPa·s at a shearing rate of 1500 s−1 and 25° C.; a roll-off reducing agent comprising a Brönsted acid or a salt thereof, having an action of lowering viscosity so that the amount of viscosity lowered is 0.01 mPa·s or more, wherein the amount of viscosity lowered is expressed by the following equation:(Amount of Viscosity Lowered)=(Viscosity of Standard Polishing Composition)−(Viscosity of Roll-Off Reducing Agent-Containing Polishing Composition),wherein the standard polishing composition is prepared which comprises 20 parts by weight of an abrasive, said abrasive being high-purity alumina having Al2O3 purity of 98.0% by weight or more composed of α-type co-random crystal, 1 part by weight of citric acid, and 79 parts by weight of water; the roll-off reducing agent-containing polishing composition is prepared which comprises 20 parts by weight of an abrasive, said abrasive being high-purity alumina having Al2O3 purity of 98.0% by weight or more composed of α-type co-random crystal, 1 part by weight of citric acid, 78.9 parts by weight of water and 0.1 parts by weight of a roll-off reducing agent; and the viscosity is a viscosity at a shearing rate of 1500 s−1 and 25° C. The polishing composition can be favorably used in polishing the substrate for precision parts.

A polishing composition containing a silica, an acid, a surfactant, and water, wherein (a) the acid has solubility in water at 25° C. of 1 g or more per 100 g of an aqueous saturated solution; (b) the surfactant is a sulfonic acid represented by the formula (1) or (2), or a salt thereof; and (c) the polishing composition has a pH of a specified range; and a polishing process of a substrate using the polishing composition are provided. The polishing composition is suitably used, for example in polishing a substrate for disk recording media such as magnetic disks, optical disks and opto-magnetic disks.

The invention belongs to the technical field of display, and particularly relates to an organic electroluminescent device, in particular to an efficient fluorescent device. According to the invention,a light emitting layer includes a thermally-activated delayed fluorescence material, a first host material, and a fluorescent dye; and a hole transport layer can form an interfacial exciplex with thefirst host material and further sensitize the fluorescent dye by using the thermally-activated delayed fluorescent material as a sensitizer. According to thethermally-activateddelayed fluorescence sensitized fluorescence (TSF) organic electroluminescent device prepared by the invention, the external quantum efficiency of the device exceeds the external quantum efficiency of a traditional fluorescent device by about 5%, the light-emitting efficiency of the fluorescent OLED device is greatly improved, and meanwhile, the device has the advantages of low turn-on voltage, low roll-off and the like.

The invention provides a bridge type GaN device and a preparation method thereof. The preparation method comprises the steps of providing a semiconductor substrate with a buffer structure and an epitaxial structure, forming a passivation layer on the epitaxial structure, preparing a source electrode and a drain electrode, preparing a gate trench, and forming a bridge type gate structure. Accordingto the invention, the power density of a transistor is increased by stacking a plurality of two-dimensional electron gas channels; through the design of the bridge type gate structure, based on a gate embedded in the epitaxial structure, the drain current is controlled by modulating the width of two-dimensional electron gas through a transverse gate electric field, so that the roll-off of transconductance derived from electron speed modulation is reduced, the peak value of transconductance is reduced, the planarization of transconductance change is realized, and the linearity of a device is improved; based on the design of a suspended bridge type gate structure, a high electric field area on the surface is eliminated, the problems of caused current attenuation and collapse are solved, thelack of a contact top gate also eliminates a vertical electric field at a gate drain end, the inverse piezoelectric effect is greatly inhibited, and the reliability is improved.

The invention discloses a full-fluorescence type white light organic light-emitting diode and a preparation method thereof. A light-emitting layer of OLEDs is formed by combining a red light-emittinglayer, a spacer layer and a blue light-emitting layer. The red light emitting layer is formed by jointly doping a phosphorescent sensitizer and a red light fluorescent object into a host material; thephosphorescent sensitizer is Ir(tptpy)2(acac), and the doping concentration of the phosphorescent sensitizer is 5-15wt.% of that of the main body material; the spacer layer is formed by blending TCTAand Bepp2 according to the weight ratio ranging from 3: 1 to 1: 3. and the blue light emitting layer is formed by doping a blue light fluorescent object material into a TTA host material. According to the organic electroluminescent device, a mode of combining TTA and phosphorescence sensitized fluorescence is adopted, and the bipolar spacer layer is introduced at the same time, so triplet excitons of the blue light emitting layer and the red light emitting layer are efficiently utilized at the same time through two different mechanisms; in addition, a green light fluorescent material is dopedin the electron transport layer, the prepared OLEDs have the characteristics of high efficiency, low roll-off, long service life and stable spectrum.

The invention relates to a stacked white light organic light emitting diode, which is composed of an anode, a first electroluminescent unit, a charge generating unit, a second electroluminescent unit and a cathode, the first electroluminescent unit and the second electroluminescent unit The light-emitting layer is a symmetrically doped sandwich light-emitting layer structure capable of emitting two colors. The colors of the light emitted by the first electroluminescent unit and the second electroluminescent unit are different, and the wavelength bands of the emitted light are complementary, and they are mixed to form a three-color or Four-color broad-spectrum white light emission. The stacked white organic light-emitting diode of the present invention realizes three-color or four-color high-efficiency, color quality and color stability white light emission only by connecting two electroluminescent units with a charge generation unit, and has a simple structure, easy preparation process, and easy industrialization. chemical production.

Embodiments provide a polishing composition containing colloidal silica, pulverized wet-process silica particles, and a water-soluble polymer compound. According to at leaset one embodiment, the water-soluble polymer compound is a copolymer containing a structural unit derived from an unsaturated aliphatic carboxylic acid and a structural unit derived from an unsaturated amide.

The invention relates to a boron-containing organic compound and application thereof. The boron-containing organic compound has a structure shown in a general formula (I): the boron-containing organic compound forms a B-containing fused ring compound by adopting a main structure of the structure shown in the general formula (1) and combining with the selection of each substituent group, so that the rigidity and the stability of material molecules are conveniently improved, and therefore, the service life of a device is prolonged. The organic compound can be used as a blue light object material, and can be matched with a proper host material, so that the luminous efficiency and the service life of the organic compound as an electroluminescent device can be improved, and meanwhile, a solution of the luminescent device which is low in manufacturing cost, high in efficiency, long in service life and low in roll-off is provided.

The invention belongs to the field of organic light-emitting diodes, and discloses a phosphorescence-sensitized fluorescent organic light-emitting diode. The phosphorescence-sensitized fluorescent organic light-emitting diode includes a substrate, an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, an electron transport layer, an electron injection layer and a cathode stacked in sequence; the light-emitting layer is composed of The phosphorescent sensitizer and the host luminescent material doped with fluorescent guest are composed. The device involved in the invention adopts the method of combining phosphorescent material and fluorescent material and co-doping in the main body, realizes 100% exciton utilization rate, and makes the prepared OLEDs have the characteristics of high efficiency and low roll-off.

The invention provides a bridge-type GaN device and a preparation method thereof. The preparation includes: providing a semiconductor substrate with a buffer structure and an epitaxial structure, forming a passivation layer on the epitaxial structure, preparing a source electrode and a drain electrode, and preparing a gate trench slots to form a bridge gate structure. The present invention increases the power density of the transistor by stacking multiple two-dimensional electron gas channels; through the design of the bridge gate structure, based on the gate buried in the epitaxial structure, the width of the two-dimensional electron gas is modulated by the lateral gate electric field To control the drain current, reduce the roll-off of the transconductance derived from electron velocity modulation, reduce the peak value of the transconductance, realize the flattening of the transconductance change, and improve the linearity of the device; the present invention is based on the suspended bridge gate The design of the electrode structure eliminates the high electric field area on the surface, and solves the current attenuation and collapse effects caused by it. The lack of contact with the top gate also eliminates the vertical electric field at the gate and drain terminals, greatly suppressing the reverse piezoelectric effect and improving reliability.

The invention relates to a phosphorescent organic light-emitting diode. The organic light-emitting layer is composed of three layers of light-emitting layer materials, wherein the first light-emitting layer is located on the side of the hole transport layer, and is composed of a hole transport type material as the main material and doped with a phosphorescent light emitting material. ; The third light-emitting layer is located on the side of the electron-transporting layer, and is composed of an electron-transporting material as the main material and doped with a phosphorescent light-emitting material; the second light-emitting layer is located between the first light-emitting layer and the third light-emitting layer, and is made of a hole-transporting material It is mixed with electron-transporting materials as the host material and doped with phosphorescent materials. The device of the invention can realize high device efficiency and extremely small efficiency roll-off, and the device preparation process is simple and repeatable.

The present invention discloses carbazole derivatives as shown in formula (1)-(3): the present invention also discloses that the above-mentioned carbazole derivatives are used as host materials in OLED organic light-emitting layers or in the preparation of electroluminescent devices Applications. The above-mentioned carbazole derivatives have a high triplet state and exhibit bipolar transport properties at the same time, and the carrier mobility is high, and the electron-hole matching is more balanced, which is conducive to the formation of excitons. It is used in organic electroluminescent blue light devices Excellent performance, low voltage, high efficiency.