Back contact silicon solar cells, valued for their aesthetic appeal by removing grid lines on the sunny side, find applications in buildings, vehicles and aircrafts, enabling self-power generation without compromising appearance^1-3. Patterning techniques arrange contacts on the shaded side of the silicon wafer, offering benefits for light incidence as well. However, the patterning process complicates production and causes power loss. Here we employ lasers to streamline back contact solar cell fabrication and enhance power conversion efficiency. Our approach produces the first silicon solar cell to exceed 27% efficiency. Hydrogenated amorphous silicon layers are deposited on the wafer for surface passivation and collection of light-generated carriers. A dense passivating contact, diverging from conventional technology practice, is developed. Pulsed picosecond lasers at different wavelengths are used to create back contact patterns. The developed approach is a streamlined process for producing high-performance back contact silicon solar cells, with a total effective processing time of about one-third that of emerging mainstream technology. To meet terawatt demand, we develop rare indium-less cells at 26.5% efficiency and precious silver-free cells at 26.2% efficiency. The integration of solar solutions in buildings and transportation is poised to expand with these technological advancements.

背接触硅太阳能电池通过去除阳光面的网格线而因其美学吸引力而受到重视，可用于建筑物、车辆和飞机，在不影响外观的情况下实现自发电^1-3。图案化技术将触点安排在硅晶片的阴影面上，也有利于光入射。然而，图案化过程使生产复杂化并导致功率损失。在这里，我们采用激光器来简化背接触太阳能电池的制造并提高功率转换效率。我们的方法生产出第一个效率超过 27% 的硅太阳能电池。氢化非晶硅层沉积在晶圆上，用于表面钝化和收集发光载流子。开发了一种与传统技术实践不同的密集钝化触点。不同波长的脉冲皮秒激光器用于创建背接触图案。开发的方法是生产高性能背接触硅太阳能电池的简化工艺，总有效加工时间约为新兴主流技术的三分之一。为了满足太瓦级需求，我们开发了效率为 26.5% 的稀有无铟电池和效率为 26.2% 的珍贵无银电池。随着这些技术进步，太阳能解决方案在建筑和交通中的集成有望扩大。