As a key material affecting the conductivity of solar cells, a series of factors such as height, width, and number of solar cell grid wires will determine the photoelectric conversion rate of solar cells. Therefore, after the solar cells are screen-printed and cleaned and texturized, solar cell manufacturers often need to measure them scientifically and reliably through precise and scientific testing equipment to ensure that their subsequent production can be carried out smoothly and effectively.

The busbar of the solar cell is an important part of the metal electrode on the front side of the solar cell, and its main function is to collect and transmit photogenerated carriers, so as to realize the electric energy conversion of solar energy. Among them, the design of the busbar has an important impact on the performance of the solar cell, so it is necessary to comprehensively consider the number, width, height and shape of the busbar to achieve the best photoelectric conversion rate and output power.

● The number of busbars determines the distance between busbars, which affects the transmission path and shading loss of transverse current. The higher the number of busbars, the shorter the transmission path of the transverse current, the smaller the string resistance, and the higher the fill factor and output power. However, the higher the number of busbars, it also means that the busbars occupy more light-receiving area, the greater the shading loss, the lower the short-circuit current and photoelectric conversion rate.

● The width of the busbar determines the cross-sectional area of the busbar, which affects the resistance and shading loss of the busbar. The smaller the width of the busbar, the smaller the cross-sectional area of the busbar, the greater its resistance, and the lower the fill factor and output power. However, the smaller the width of the busbar, the smaller the busbar line occupies less light-receiving area, the smaller the shading loss, the higher the short-circuit current and the higher the photoelectric conversion rate. Therefore, the width of the busbar needs to find a balance between reducing the series resistance and shading loss to optimize the performance of the solar cell.

● The height of the busbar determines the cross-sectional area of the busbar, which affects the resistance and contact resistance of the busbar. The higher the height of the busbar, the larger the cross-sectional area of the busbar, the smaller the resistance of the busbar, the smaller the series resistance, and the higher the fill factor and output power. However, the higher the height of the busbar, the smaller the contact area between the busbar and the cell, the greater the contact resistance, and the lower the fill factor and output power.

● The shape of the busbar determines the shading effect and optical gain of the busbar. The shape of the grid line can be divided into a planar grid line and a three-dimensional bus line. Flat grid refers to a grid with a rectangular or trapezoidal cross-section of the grid line, which has a large shading effect and a small optical gain. Three-dimensional grid refers to the grid line with a triangular or arc-shaped cross-section, which has a small shading effect and a large optical gain. The three-dimensional grid can use the refraction and reflection of light to reintroduce the partially shaded light into the solar cell, thereby improving the photoelectric conversion rate of the solar cell. Therefore, the shape of the grid line needs to find a balance between reducing the shading effect and increasing the optical gain to optimize the performance of the solar cell.