Optimization Of High Square Resistance Solar Cell

In the process of solar cell production, the PN junction formed during diffusion is called the heart of the solar cell. The sheet resistance has a significant impact to the battery performance, it is necessary to study the optimal resistance and the way to improve cell conversion efficiency. In addition, the sintering p conditions are closely related with diffusion doping processes. As long as the diffusion distribution is changed, we must optimize the sintering process accordingly.Today, most of the sheet resistance of the solar cell is50Ω-60Ω, which is to ensure that the gate electrode line can form a good ohmic contact with the cells during the screen printing. However, the heavily doped surface of the battery causes the carriers serious compound, as a result, the short-circuit current and open-circuit voltage are low. Therefore, if we can ensure a good ohmic contact of the battery, and effectively improve the short-circuit current and open circuit voltage, it will greatly improve the efficiency of solar cells.This thesis focuses on the actual situation of the production line, to make a solution of high square resistance. Remain the process the same and when a square resistance is elevated only, the short-circuit current rises constantly and when elevated70Ω, the open-circuit voltage approaches saturation. While the fill factor of the solar cell descends because of the elevation of the square resistance. The efficiency of solar cells can reach a maximum by70Ω.In this thesis, based on the basic solar cell manufacturing process technology, we explain the basic characteristics of the solar cell(short-circuit current, open-circuit voltage), output-characteristic, conversion efficiency and so on. We deeply understand the basic principle of Phosphorus diffusion. We analyze the current situation of the diffusion process, and design experiments to obtain high square resistance. Finally we improve the conversation efficiency.