41results about How to "Improve current characteristics" patented technology

A nitride semiconductor device is provided, in which a superlattice strain buffer layer using AlGaN layers having a low Al content or GaN layers is formed with good flatness, and a nitride semiconductor layer with good flatness and crystallinity is formed on the superlattice strain buffer layer. A nitride semiconductor device includes a substrate; an AlN strain buffer layer made of AlN formed on the substrate; a superlattice strain buffer layer formed on the AlN strain buffer layer; and a nitride semiconductor layer formed on the superlattice strain buffer layer, and is characterized in that the superlattice strain buffer layer has a superlattice structure formed by alternately stacking first layers made of Al_xGa_1−xN (0≦x≦0.25), which further contain p-type impurity, and second layers made of AlN.

The invention discloses a permanent magnet synchronous motor predicted current control method and system based on FOSMC; the method comprises the following steps of carrying out comparing on the rotorangular speed and a given rotating speed to obtain a rotating speed difference, and inputting the rotating speed difference into a fractional order sliding mode controller; next, enabling an equivalent current of a dq axis at the current moment to pass through a sliding mode disturbance observer to obtain a voltage compensation quantity and a current estimation value under the parameter change, and enabling the current estimation value and the reference current at the next moment to be input into a non-differential-beat current prediction controller; and finally, carrying out compensating onthe obtained voltage vector and the voltage compensation amount of the dq axis at the current moment, carrying out coordinate transformation, space vector modulation and inversion, and obtaining a three-phase voltage to the permanent magnet synchronous motor, so that the stable operation of the motor is ensured. According to the method and the system disclosed by the invention, fractional order calculus and sliding mode variable structure control are combined, the fractional order calculus has more freedom degree, and the shaking of the system in the sliding mode process can be weakened, so that the control precision of the rotating speed is improved.

The invention provides a preparation method of a low-temperature polycrystalline silicon film. According to the method, a buffer layer and a noncrystalline silicon layer are firstly formed on a base plate, then, primary laser annealing treatment is carried out on the noncrystalline silicon layer so that the noncrystalline silicon layer is converted into a polycrystalline silicon growth bottom layer, next, the polycrystalline silicon growth bottom layer is subjected to etching treatment so that the surface of the polycrystalline silicon growth bottom layer obtained in the primary laser annealing treatment gradually becomes flat, subsequently, the polycrystalline silicon growth bottom layer is subjected to secondary annealing treatment, and the polycrystalline silicon film is obtained. The surface roughness of the low-temperature polycrystalline silicon film prepared by the method is low, and the current characteristics of subsequently prepared polycrystalline silicon film transistors are good.

Provided is a thin film transistor having an oxide semiconductor material for an organic light emitting diode display and a method for manufacturing the same. The organic light emitting diode display comprises: a gate electrode formed on a substrate; a gate insulating layer formed on the gate electrode; a semiconductor layer formed on the gate insulating layer to overlap with the gate electrode, and including a channel area and source and drain areas which extend from the channel area to both outsides, respectively and are conductorized; an etch stopper formed on the channel area and exposing the source area and the drain area; a source electrode contacting portions of the exposed source electrode; and a drain electrode contacting portions of the exposed drain electrode.

A method for manufacturing a thin film transistor with improved current characteristics and high electron mobility. According to the method, when an amorphous silicon thin film is crystallized into a polycrystalline silicon thin film by metal-induced crystallization, annealing conditions of the amorphous silicon thin film and the amount of a metal catalyst doped into the amorphous silicon thin film are optimized to reduce the regions of a metal silicide distributed at grain boundaries of the polycrystalline silicon thin film. In addition, oxygen (O₂) gas or water (H₂O) vapor is supplied to form a passivation film on the surface of the polycrystalline silicon thin film.

In a multilayered photodiode and a method of manufacturing the same, the multilayered photodiode comprises: a transparent substrate; a gate insulating film formed on the transparent substrate; a first metal layer formed on the gate insulating film; a semiconductor layer formed on the first metal layer so as to be in contact with the first metal layer; and a second metal layer formed on the semiconductor layer so as to be in contact with the semiconductor layer. The photodiode is vertically multilayered, and has a metal-insulator-metal (MIM) structure in which a P-N region is replaced by a metal, and in which a light-receiving region does not block incident light.

The present invention relates to a novel organic luminescent compound and an organic electroluminescence device containing the same. The compounds according to the present invention have high luminous efficiency and long operation lifetime. Therefore, they can produce an organic electroluminescent device which improves power consumption.

The invention relates to a pyrene derivate organic electroluminescence material and a preparation method thereof and an organic electroluminescence device, and relates to the field of luminescence materials. The pyrene derivate organic electroluminescence material is high in electronic transmission efficiency, so that the crystallizing can be prevented during the device manufacturing; the pyrene derivate organic electroluminescence material easily forms a layer, so that the current property of the device can be improved. The preparation method of the pyrene derivate organic electroluminescence material is characterized in that the raw materials are easily obtained; the processes are simple; the industrial production applies. The organic electroluminescence device is applicable to a planar luminescence bodies such as surface plates of various electronic devices like a wall-hung flat-panel television, a light source, a label and a logo of a copying machine, a printer, a liquid crystal display device or an instrument. Besides the organic electroluminescence device, the pyrene derivate organic electroluminescence material can also be applied to the fields such as the electronic photoreceptor field, the photoelectric conversion element field, the solar cell field and the image sensor field.

The present invention relates to a novel compound and an organic electroluminescent device containing the same. Since the compounds according to the present invention have high efficiency in transporting electrons, crystallization could be prevented when manufacturing the device, and since they are adaptable in the formation of the layers, the current characteristic of the device is improved, and finally they can manufacture an organic electroluminescent device having lowered driving voltage, advanced power efficiency, and improved light emitting efficiency and lifetime characteristic compared with devices comprising the conventional materials.

The invention provides a triphenylene derivate and an organic electroluminescence device, and belongs to the technical field of organic electroluminescence materials. The compound has the structure asshown in formula (I). According to the triphenylene derivate, triphenylene and benzimidazole are condensed, so that the obtained material is high in glass transition temperature and is capable of avoiding crystalizing; the synthesizing method is simple, and easy to operate; the organic electroluminescence device prepared through the triphenylene derivate is high in luminescence efficiency and lowin driving voltage.

The invention provides a pyrene derivative and an organic electroluminescence device thereof, and belongs to the technical field of an organic electroluminescence material. The compound has a structure shown as a formula (I). Pyrene and benzoglioxaline are compounded, so that the obtained material has excellent electron transmission capability and high glass transition temperature and can achievethe effect of preventing crystallization. The synthesis method is simple; the operation is easy; the organic electroluminescence device prepared from the pyrene derivative shows the advantages of lowdriving voltage and high luminous efficiency and belongs to an organic electroluminescence material with good performance.

The invention provides a phenanthrene derivative and an organic light-emitting device thereof, and belongs to the technical field of organic photoelectric materials. The composition has the structureshown in the formula (I), the obtained phenanthrene derivative has the excellent electronic transmission capability, high glass-transition temperature and the effect of preventing crystallization by condensing phenanthrene and benzimidazole. The synthesis method is simple and easy to operate, the organic light-emitting device prepared by using the phenanthrene derivative has the advantages of being low in driving voltage and high in light-emitting efficiency, and is an organic light-emitting material with excellent performance.

Provided are a composition including a dopant and a matrix, and an organic electroluminescent device. The invention relates to a composition. The composition includes one or more matrix compounds, presented by the chemical formula 1, and also includes one or more dopant compounds, presented by the chemical formula 2.

The present invention relates to a novel organic electroluminescent compound and an organic electroluminescent device containing the same. Since the organic electroluminescent compounds according to the present invention have high efficiency in transporting electrons, crystallization may be prevented when manufacturing a device. Further, the compounds have good layer formability and improve the current characteristics of the device. Therefore, they can produce an organic electroluminescent device having lowered driving voltages and enhanced power efficiency.

The invention provides a perylene derivative and an organic electroluminescence device thereof and belongs to the technical field of organic photo-electric materials. The perylene derivative is of a structure of formula (I) as shown in the description. Due to thickening of perylene and benzimidazole, the obtained material has a high vitrification transformation temperature, in addition, a crystallization prevention function can be achieved, a synthesis method is simple and easy to operate, and the organic electroluminescence device made of the perylene derivative has good light emission efficiency and low driving voltages.

The invention relates to an organic electroluminescence material and a preparing method thereof and an organic electroluminescent device, and relates to the field of a luminescent material. The purpose is providing the organic electroluminescence material with high luminescence efficiency, long device life, and a novel structure with appropriate color coordinates and the preparing method thereof and the organic electroluminescent device. The provided organic electroluminescence material has high electronic transmission efficiency, thereby crystallization can be prevented during manufacturing the device, a layer can be easily formed, and therefore the characteristics of electric current of the device are improved. The preparing method for the provided organic electroluminescence material iseasily-obtained in raw materials, is simple in technology, and is suitable for industrial production.