Laser-Induced Periodic Surface Structures on Layered GaSe Crystals: Structural Coloring and Infrared Antireflection
Stanislav O. Gurbatov, Yulia Borodaenko, Eugeny Mitsai, Evgeny Modin, Alexey Zhizhchenko, Artem Cherepakhin, A. V. Shevlyagin, Sergey Syubaev, Alexey P. Porfirev, Svetlana N. Khonina, Alexander Yèlisseyev, S. Lobanov, L. I. Isaenko, Evgeny L. Gurevich, Aleksandr A. Kuchmizhak
Abstract
We study structural and morphological transformations caused by multipulse femtosecond-laser exposure of Bridgman-grown ϵ-phase GaSe crystals, a van der Waals semiconductor promising for nonlinear optics and optoelectronics. We unveil, for the first time, the laser-driven self-organization regimes in GaSe allowing the formation of regular laser-induced periodic surface structures (LIPSSs) that originate from interference of the incident radiation and interface surface plasmon waves. LIPSSs formation causes transformation of the near-surface layer to amorphous Ga 2 Se 3 at negligible oxidation levels, evidenced from comprehensive structural characterization. LIPSSs imprinted on both output crystal facets provide a 1.2-fold increase of the near-IR transmittance, while the ability to control local periodicity by processing parameters enables multilevel structural color marking of the crystal surface. Our studies highlight direct fs-laser patterning as a multipurpose application-ready technology for precise nanostructuring of promising van der Waals semiconductors, whose layered structure restricts application of common nanofabrication approaches.