3results about How to "Improve doping uniformity" patented technology

This invention discloses the preparation and application of core-shell structured hollow glass microsphere precursor particles, comprising: mixing water glass with water, then removing sodium ions with a cation exchange resin to obtain a silicate aqueous solution; dissolving metal nitrate and boric acid into a saturated aqueous solution, adding it to the silicate aqueous solution under magnetic stirring to obtain a uniformly doped transparent mixed solution, and spray drying to obtain core-shell structured hollow glass microsphere precursor particles. This invention pre-forms relatively large pores within the precursor particles to obtain core-shell structured hollow glass microsphere precursor particles, which can effectively shorten the foaming and spheroidizing time, reduce incompletely foamed particles, and improve the yield and performance of hollow glass microspheres. This invention uses molecular-level water glass as the main raw material, completing part of the silicate formation and cross-linking reaction during the process, replacing the bonding and aggregation of particles prepared by traditional soft chemical methods with chemical bonding, thus enhancing the compressive strength of the precursor particles.

This invention discloses a method for element doping of a thin-film solar cell and its absorber layer, relating to the field of thin-film solar cell technology. By immersing the activated absorber layer in a salt solution of a predetermined dopant element and simultaneously applying an exogenous inducing variable, the predetermined element is doped. During the doping process, the diffusion of dopant ions into the grain boundaries and lattice interior of the absorber layer is promoted, ensuring that the element is not affected by the surface morphology, hydrophilicity / hydrophobicity, internal or edge structure of the absorber layer. This solves the problems of difficult-to-control element doping uniformity, poor process stability, and low effective doping activation rate in existing technologies. It achieves the goal of diffusive doping of p-type elements in the absorber layer with high doping uniformity, high doping activation rate, controllable doping process, and compatibility with existing processes.

The invention relates to a low-junction capacitance symmetric transient voltage suppressor diode and a preparation method thereof. The preparation method comprises the steps of silicon wafer cleaning, N-type doping, oxidation, photoetching, oxide layer removal, slotting corrosion, passivation, surface corrosion, electrode manufacturing, metal stripping and cutting. Wherein in the N-type doping step, POCl3 is used as a gas-phase phosphorus source, double-sided synchronous diffusion is carried out on a silicon wafer, and a shallow junction N-type region with the junction depth of 1.5-3.0 microns is formed; in the oxidation step, the silicon wafer with the shallow junction N-type region is subjected to high-temperature oxidation in an oxygen-containing atmosphere, phosphorus atoms are driven to be redistributed from the surface to the inside, a doping section with the phosphorus concentration gradually changing from the surface of the silicon wafer to the inside is formed, and a surface oxidation layer is synchronously grown. According to the preparation method disclosed by the invention, the junction capacitance is reduced, and the symmetry, the response speed and the pulse endurance capability of the bidirectional transient voltage suppression diode are improved by improving the doping uniformity.