Analysis of different laser cutting conditions on electrical characteristics of half-cut HJT solar cells

Nowadays, as wafer sizes continue to increase in the solar industry, the use of half-cut cells has gained attention as a means of increasing the current output by reducing resistive losses. The laser scribing technology cannot increase the output power, as the laser process can cause losses due to laser-induced damages. Therefore, laser scribing losses have a more substantial influence on the photovoltaic electrical characteristic. It is significantly impacted by high-efficiency solar cells such as heterojunction technology (HJT) and passivated contact solar cells. Currently, infra-red (IR) and non-destructive cutting (NDC) technology are both very useful cutting technologies for halved solar cells. IR technology has been already known conventional scribing method and has been considerably researched. However, how NDC cutting causes damage and the critical factors to reduce the damage still lack comprehensive research. Hence, in this research, we studied how different laser-cutting conditions affect the electrical characteristics of half-cut HJT solar cells. Firstly, IR laser scribing at the front and rear surfaces of HJT cells was demonstrated to compare surface damage dependence. Next, we exploited state-of-the-art cutting technology NDC with various cutting conditions, such as laser scribing powers and scan speeds. The results show that NDC cutting technology shows that the second laser power and scan speeds impacted output performance. Therefore, the NDC method shows a higher power efficiency than conventional IR scribing technology, with improvements of 2.6% in fill factor and 0.63 W in output power.