Effects of screen printing and sintering processing of front side silver grid line on the electrical performances of multi-crystalline silicon solar cells

In this paper, the influence of screen-printing technology, sintering temperature, and the belt speed of sintering furnace on electrical properties of solar cells were researched. It is found that the morphology and aspect ratio of grid line are strongly influenced by printing parameters including the snap-off distance, the squeegee pressure and the squeegee speed. A number of comparative experiments showed that the electrical performance of solar cells was the best when the snap-off distance is 1200 µm, the squeegee pressure is 75 N, and the squeegee speed is 220 mm/s. Meanwhile, the surface morphology of the front electrode grid line prepared with the above optimum technology parameter is smooth and dense, and possesses good aspect ratio. To better understand the contact quality, the influence of sintering peak temperature on the electrical performance of solar cells was deeply studied. The results show that when the peak temperature was 900 °C, the series resistance (R s ) possesses the minimum value and the open circuit voltage (V oc ), fill factor (FF), and conversion efficiency (E ff ) all possess the maximum values. The effect of belt speed of sintering furnace on the electrical performance of the cells was also investigated. It is found that the electrical performance parameters were the optimal at the belt speed of 245 in/min.