High-Throughput Indirect Gravure Printing Applied to Low-Temperature Metallization of Silicon-Based High-Efficiency Solar Cells

Herein, this work is dedicated to a both exotic and promising printing technique in silicon (Si) photovoltaics (PV). Indirect gravure printing is investigated as a metallization technique focusing on low-temperature applications, such as Si heterojunction (SHJ) and perovskite Si tandem solar cells. One advantage of this rotary printing technique is that its components are very durable. From graphical industry, it is known that gravure cylinders show almost no wearing during multiple printing. Additionally, rotary printing techniques offer great throughput. Therefore, indirect gravure printing can reduce costs significantly in PV production. In this work, short process cycle times of 0.9 s cell-1 for industrial wafers (edge length of 156.75 mm) are demonstrated. Using an appropriate production platform even enables cycle times of down to 0.5 s cell-1. Busbarless SHJ half cells with non-optimized gravure-printed front grids reach a mean photoconversion efficiency that is (1.7 ± 0.5) %abs lower compared to screen-printed reference samples, however, cycle time is reduced. The metal contacts exhibit a mean shading width of (65 ± 16) μm and an average height of (5 ± 1) μm. Applied to SHJ solar cells’ rear, such metallization can replace screen-printed contacts with 0.1%abs efficiency loss only, as device simulations reveal.