English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

High-Pressure Core Structures of Si Nanoparticles for Solar Energy Conversion

MPS-Authors
There are no MPG-Authors available
External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Wippermann, S. M., Vörös, M., Rocca, D., Gali, A., Zimanyi, G. T., & Galli, G. (2013). High-Pressure Core Structures of Si Nanoparticles for Solar Energy Conversion. Physical Review Letters, 110(4): 046804. doi:10.1103/PhysRevLett.110.046804.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0026-C15E-5
Abstract
We present density functional and many body perturbation theory calculations of the electronic, optical, and impact ionization properties of Si nanoparticles (NPs) with core structures based on high-pressure bulk Si phases. Si particles with a BC8 core structure exhibit significantly lower optical gaps and multiple exciton generation (MEG) thresholds, and an order of magnitude higher MEG rate than diamondlike ones of the same size. Several mechanisms are discussed to further reduce the gap, including surface reconstruction and chemistry, excitonic effects, and embedding pressure. Experiments reported the formation of BC8 NPs embedded in amorphous Si and in amorphous regions of femtosecond-laser doped "black silicon." For all these reasons, BC8 nanoparticles may be promising candidates for MEG-based solar energy conversion. DOI: 10.1103/PhysRevLett.110.046804