Enhancing light trapping of macroporous silicon by alkaline etching: application for the fabrication of black Si nanospike arrays

Gabriel Loget (1) , Antoine Vacher (1) , Bruno Fabre (1) , Francis Gouttefangeas (2) , Loïc Joanny (2) , Vincent Dorcet (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 C.M.E.B.A. - Centre de Microscopie Electronique à Balayage et microAnalyse

The synthesis of highly absorbing silicon (black Si (BSi)) is a very active research topic with promising applications in the field of sustainable energies, ultrasensitive sensing and antibacterial materials. Here, we show that extended alkaline etching of macroporous Si, fabricated by photoelectrochemical etching drastically influence the surface structures as well as their optical properties. We demonstrate that this treatment can considerably improve the light trapping of the surface and we finally show that it is possible to use it for fabricating very quickly highly-absorbing arrays of sharp and crystalline BSi nanospikes (NSpikes).

Domains: Chemical Sciences

Gabriel Loget, Antoine Vacher, Bruno Fabre, Francis Gouttefangeas, Loïc Joanny, et al.. Enhancing light trapping of macroporous silicon by alkaline etching: application for the fabrication of black Si nanospike arrays. Materials Chemistry Frontiers, 2017, 1 (9), pp.1881-1887. ⟨10.1039/C7QM00191F⟩. ⟨hal-01616129⟩