AUTHOR=Wen Zhidong , Shi Haiyan , Yue Song , Li Man , Zhang Zhe , Wang Ran , Song Qi , Xu Ziye , Zhang Zichen , Hou Yu 

TITLE=Large-Scale Black Silicon Induced by Femtosecond Laser Assisted With Laser Cleaning

JOURNAL=Frontiers in Physics

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2022.862605

DOI=10.3389/fphy.2022.862605

ISSN=2296-424X

ABSTRACT=The black silicon is a promising and effective candidate in the field of photoelectric devices due to the high absorptance and broad-spectrum absorption property. The deposition around the processing area induced by the pressure of SF6, gravity, and the block of the processing chamber interferes the adjacent laser ablation and hampers uniform large-scale black silicon fabrication. To solve the problem, femtosecond laser induced black silicon assisted with laser plasma shockwave cleaning is creatively proposed in our study. The results show that higher, denser and more uniform microstructures can be obtained compared to the conventional laser induced method without laser cleaning. And the average absorptance is 99.15% in the wavelength range of 0.3-2.5 µm while that is over 90% in the range of 2.5-20 µm. In addition, the scanning pitch dependence of surface morphology is discussed and the better result is obtained in the range of 25-35 µm with 40 µm laser spot. Finally, a large-scale 50 mm × 50 mm black silicon with uniform microstructures was prepared by our method. It has been demonstrated that the deposition is effectively eliminated via our method, and the optical absorption is also enhanced significantly.  It is of great significance for realizing large-scale preparation of photoelectric devices based on black silicon, and lays the foundation for the development of laser inducing equipment and industrial application.