Real-Space Analysis of the Optical Absorption in Alternative Phases of Silicon

ORAL

Abstract

We introduce a real-space approach to understand the relationship between optical absorption and crystal structure. This approach is applied to some alternative phases of silicon in addition to the diamond structure, with a focus on the Si$_{20}$ crystal phase as a case study. We find that about 83{\%} of the enhancement in the calculated low-energy absorption in Si$_{20}$ can be attributed to reducing the differences between the on-site energies of the bonding and anti-bonding orbitals as well as to increasing the magnitude of the hopping integrals for specific Si-Si bonds. This work was supported by NSF grant No. DMR-1508412 and the DOE under Contract No. DE-AC02-05CH11231. Computational resources have been provided by DOE at Lawrence Berkeley National Laboratory's NERSC facility.

–

Authors

  • Chin Shen Ong

    • Department of Physics, UC Berkeley and Lawrence Berkeley National Lab

  • Sinisa Coh

    • Mechanical Engineering, Materials Science and Engineering, UC Riverside
    • UC Riverside

  • Marvin L. Cohen

    • Department of Physics, UC Berkeley and Lawrence Berkeley National Lab

  • Steven G. Louie

    • Department of Physics, UC Berkeley and Lawrence Berkeley National Lab
    • UC Berkeley and Lawrence Berkeley National Lab
    • University of California at Berkeley and Lawrence Berkeley National Lab
    • Physics Department, UC Berkeley and Lawrence Berkeley National Lab
    • Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory
    • Univ of California - Berkeley and Lawrence Berkeley National Lab