Black silicon
[7] For low reflectivity, the nanoscale features producing the index graded layer must be smaller than the wavelength of the incident light to avoid scattering.
Potential applications include:[8] In semiconductor technology, reactive-ion etching (RIE) is a standard procedure for producing trenches and holes with a depth of up to several hundred micrometres and very high aspect ratios.
With cryogenic RIE, the low temperature and oxygen gas achieve this sidewall passivation by forming SiO2, easily removed from the bottom by directional ions.
[36] After irradiation in the presence of a gas containing sulfur hexafluoride and other dopants, the surface of silicon develops a self-organized microscopic structure of micrometer-sized cones.
sulfur atoms are forced to the silicon surface, creating a structure with a lower band gap and therefore the ability to absorb longer wavelengths.
The nanoparticles attract electrons from the wafer's surface, oxidizing it and allowing the hydrogen fluoride to burn inverted pyramid-shaped nanopores into the silicon.
A team led by Elena Ivanova at Swinburne University of Technology in Melbourne discovered in 2012[48] that cicada wings were potent killers of Pseudomonas aeruginosa, an opportunist germ that also infects humans and is becoming resistant to antibiotics.
The three targeted bacterial species were P. aeruginosa, Staphylococcus aureus and Bacillus subtilis, a wide-ranging soil germ that is a cousin of anthrax.
A group led by Gagik Ayvazyan at National Polytechnic University of Armenia in Yerevan demonstrated in 2023 that needle-like nanotextures provide a feasible light-management solution for perovskite/silicon tandem solar cells.
