Real-space study of the optical absorption in alternative phases of silicon

Abstract

We introduce a real-space approach to understand the relationship between optical absorption and crystal structure. We apply this approach to alternative phases of silicon, with a focus on the Si${}_{20}$ crystal phase as a case study. We find that about 83% of the changes in the calculated low-energy absorption in Si${}_{20}$ as compared to Si in the diamond structure can be attributed to reducing the differences between the on-site energies of the bonding and anti-bonding orbitals as well as increasing the hopping integrals for specific Si-Si bonds.

8 pages, 8 figures

References in corpus (5)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• High-pressure phases of silane
• Exponential localization of Wannier functions in insulators
• Phonon-assisted optical absorption in silicon from first principles
• Towards Direct-Gap Silicon Phases by the Inverse Band Structure Design Approach