Ultrastable Silicon Nanocrystals due to Electron Delocalization

• Published in: Nano letters Vol. 11; no. 12; pp. 5477 - 5481
• Main Author: Vach, Holger
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 14-12-2011
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Devices; Electron states; Exact sciences and technology; Fullerenes and related materials; Infrared; Infrared and raman spectra and scattering; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Mathematical analysis; Methods of electronic structure calculations; Nanocrystalline materials; Nanocrystals; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Physics; Self assembly; Silicon; Solar cells; Spectra; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); photothermal cancer treatment; silicon aromaticity; Electron-deficiency; light emitting diodes; photovoltaics; silicon nanocrystals; Self-assembly; Density functional method; Light emitting diodes; Americium; Electron delocalization; Silicon; Nanostructures; Infrared spectra; Nanostructured materials; Nanocrystal; Photovoltaic cell
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl203275n

We report a new nanocrystalline form of silicon that gives birth to pure hydrogenated silicon nanocrystals that absorb light in the ultraviolet, visible, and infrared spectral region despite their small size of only 1 nm and without the need for expensive or toxic metal atoms. On the basis of first-principles calculations, we demonstrate that those pure, but overcoordinated silicon nanocrystals are more stable than any other known silicon nanocrystals due to electron delocalization and that they form spontaneously via self-assembly. Therefore, we predict their immediate application in fields ranging from photovoltaic and light-emitting devices to photothermal cancer treatment.