Metallic subnanometer porous silicon: A theoretical prediction

In the present work, T-Si, a silicon-based counterpart of T-carbon, has been designed with the aid of density functional theory (DFT) calculations. Its stability has been fully confirmed from energetic, mechanical, lattice dynamic, and thermodynamic aspects. Due to the space extrusion, the delocalized electrons on the Si-4 tetrahedrons are squeezed onto the inter-tetrahedron Si-Si bonds, which therefore leads T-Si to be metallic. Furthermore, the electronic conductivity of this new material has also been predicted and discussed in this work. This new silicon allotrope with a low density of 0.869 g/cm(3) can even floats on water. This designed ultralight form of Si paves the way for the applications in the fields of spacecraft and automobiles in the future.

Automated summary

In this work, a silicon-based counterpart of T-carbon, named T-Si, was designed using density functional theory calculations. The stability of T-Si was confirmed from energetic, mechanical, lattice dynamic, and thermodynamic aspects. Due to space extrusion, delocalized electrons on Si-4 tetrahedrons are squeezed onto inter-tetrahedron Si-Si bonds, making T-Si metallic. Its electronic conductivity was predicted and discussed, and with a low density of 0.869 g/cm(3), T-Si can even float on water, paving the way for future spacecraft and automobile applications.