Quasi‐Omnidirectional Ultrathin Silicon Solar Cells Realized by Industrially Compatible Processes

Abstract

AbstractUltrathin crystalline silicon (c‐Si) solar cells provide advantages in reducing the use of c‐Si material and being flexible, but there are several challenges that need to be conquered, such as limited optical absorption, high sensitivity to surface recombination, and complicated fabrication issues. Here, all‐solution‐processed Si nanopyramids (SiNPs) are proposed as the surface texture for ultrathin c‐Si solar cells to solve the light absorption issue, whose preparation process is simple, low‐cost, and industrially compatible. Combining the SiNPs texture with good passivation technique, an efficiency of 15.1% with an open circuit voltage approaching 700 mV is realized on a 37 µm thick c‐Si solar cell. Moreover, both experimental and simulation investigation reveal that the SiNP‐textured ultrathin solar cells have quasi‐omnidirectional light absorption characteristic, showing a potential to produce higher all‐day output power compared with the Si micropyramids textured counterpart. To further reduce the cost of ultrathin c‐Si solar cells, a direct copper metallization is also investigated in replacement of silver metallization, which can result in a comparable efficiency. The present work demonstrates the conventional industrial processes for achieving low‐cost ultrathin c‐Si solar cells.