Abstract: The present invention belongs to the technical field of semiconductor devices, and discloses a power device using photoelectron injection to modulate conductivity and the method thereof. The power device comprises at least one photoelectron injection light source and a power MOS transistor. The present invention uses photoelectron injection method to inject carriers to the drift region under the gate of the power MOS transistor, thus modulating the conductivity and further decreasing the specific on-resistance of the power MOS transistor. Moreover, as the doping concentration of the drift region can be decreased and the blocking voltage can be increased, the performance of the power MOS transistor can be greatly improved and the application of power MOS transistor can be expanded to high-voltage fields.

Abstract: A high solid polyester polyol/silica nanocomposite resin with low viscosity is synthesized by an in situ polymerization method, namely conducting condensation polymerization of polyol/diacid monomer with a molar ratio of 1.1˜1.5 in the presence of colloidal silica nanoparticles with a diameter of 10˜150 nm. The resulted nanocomposite resins has a solid content of >95%, molecular weight of 1000˜5000 g/mol and hydroxyl value of 80-200 mg KOH/g, and a viscosity in the range of 800-2000 mPa.s. The viscosities are especially lower than those obtained by a blending method. The nanosilica content in the nanocomposite resin is 1˜15% (based on the total solid content of nanocomposite resin). The high solid polyester polyol/silica nanocomposite resin was curable with isocyanate or melamine to prepare high solid transparent nanocomposite coatings with obviously improved abrasion and scratch resistance, hardness, weatherability etc.