we investigate the potential to optimize the screen-printed front side metallization of silicon heterojunction (SHJ) solar cells
a grid layout is improved by increasing the number of contact fingers from 120 to 156
current possibility to push the fine-line printing process for low-temperature pastes to the limit is investigated by reducing the nominal finger width wn to 20, 18, and 15 μm
shown that even the smallest nominal width of wn = 15 μm can be printed with high quality, leading to an additional efficiency gain of Δη = +0.15%abs as well as a reduction of silver paste laydown by −5 mg
Finally, a batch of champion cells is fabricated by applying the findings of the previous experiments, which results in a maximum efficiency of ηmax = 23.2%. Compared to the reference group without optimization, this corresponds to a gain of Δη = +0.17%abs, which comes along with an additional decrease of the silver paste laydown by approximately −2 mg
Using fine-mesh screens to print very fine contacts,6, 7 even the predicted goal to reduce the silver consumption below 5 mg/Wp5 seems to be within reach.