| CSI Cells Co., Ltd. Patent applications |
| Patent application number | Title | Published |
|---|
| 20090098715 | Process for manufacturing silicon wafers for solar cell - A process for manufacturing silicon wafers for solar cell is disclosed wherein one first breaks the refined metallurgical silicon, then remove visible impurities, then performs chemical cleaning and then places the silicon into a crystal growing furnace. Gallium or gallium phosphide is added to the silicon, where the concentration of gallium atoms should be in the range from 5 ppma to 14 ppma. Crystal growth is initiated, followed by subdivision and inspection after the crystal rods or crystal bars have grown, yielding the desired silicon wafers. With this solution, the refined metallurgical silicon can be used for manufacturing of solar cells, so as to reduce the cost of materials, and it is conducive to the universal application of silicon solar cells. | 04-16-2009 |
| 20090093081 | Process of phosphorus diffusion for manufacturing solar cell - This invention discloses a process of phosphorus diffusion for manufacturing solar cell, comprising annealing a mono-crystalline silicon wafer in a nitrogen atmosphere at 900-950° C. for twenty to thirty minutes, carrying oxidation treatment in a hydrogen chloride atmosphere at 850-1050° C. to form a 10 to 30 nm thick oxide layer on the surface of said silicon wafer, diffusing from a phosphorus source at 850-900° C., until a block resistance of a material surface is controlled at 40 to 50 ohms, and the junction depth is at 0.2 to 1.0 microns, and annealing in a nitrogen atmosphere at 700-750° C. for thirty to sixty minutes to complete the phosphorus diffusion of said mono-crystalline silicon wafer. This invention allows the use of 4 N˜5 N mono-crystalline silicon as the material for manufacturing solar cells, so, the low purity material such as metallurgical silicon can be used, which greatly reduces the cost of materials. | 04-09-2009 |
| 20090091339 | Method for detection and analysis of impurity content in refined metallurgical silicon - This invention discloses a method for detection and analysis of impurity content of refined metallurgical silicon, comprising: (1) select the measuring points on the crystal rods or crystal ingots along the crystallization direction, measuring the resistivity at each measuring point and acquire the measured value of resistivity according to the distribution of crystallized fraction; (2) get the estimated value of the content of boron and phosphorus at each measuring point and calculate the estimated net redundant carrier concentration and the measured value of resistivity; (3) compare the estimated value of net redundant carrier concentration with that of the measured value, and adjust the estimated value of impurity content in the silicon material to get the new estimated net redundant carrier concentration, and use regression analysis to determine the impurity content distribution of boron and phosphorus; (4) get the average impurity content of boron and phosphorus in the silicon material according to the distribution status of impurity based on all the measuring points. This invention can detect accurately the impurity contents of boron and phosphorus in refined metallurgical silicon, while the operation is simple, low-cost and suitable for industrial applications. | 04-09-2009 |
