Exotic phase Si nanoparticles and Si-ZnS nanocomposites: New paradigms to improve the efficiency of MEG solar cells

Marton Voros, Stefan Wippermann, Adam Gali, Francois Gygi, Gergely Zimanyi, Giulia Galli

Research output: Conference contribution

Abstract

The efficiency of nanoparticle (NP) solar cells may substantially exceed the Shockley-Queisser limit by exploiting quantum confinement enhanced multi-exciton generation (MEG). However, (i) quantum confinement tends to increase the electronic gap and thus the MEG threshold beyond the solar spectrum and (ii) charge extraction through NP networks may be hindered by facile recombination. Using ab initio calculations we found that (i) Si NPs with exotic core structures such as BC8 exhibit significantly lower gaps and MEG thresholds than particles with diamond cores, and an order of magnitude higher MEG rates. (ii) We also investigated Si NPs embedded in a ZnS host matrix and observed complementary charge transport networks, where electron transport occurs by hopping between NPs and hole transport through the ZnS-matrix. Such complementary pathways may substantially reduce recombination, as was indeed observed in recent experiments. We employed several levels of theory, including DFT with hybrid functionals and GW calculations.

Original languageEnglish
Title of host publication2014 IEEE 40th Photovoltaic Specialist Conference, PVSC 2014
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages3432-3434
Number of pages3
ISBN (Electronic)9781479943982
DOIs
Publication statusPublished - okt. 15 2014
Event40th IEEE Photovoltaic Specialist Conference, PVSC 2014 - Denver, United States
Duration: jún. 8 2014jún. 13 2014

Publication series

Name2014 IEEE 40th Photovoltaic Specialist Conference, PVSC 2014

Other

Other40th IEEE Photovoltaic Specialist Conference, PVSC 2014
CountryUnited States
CityDenver
Period6/8/146/13/14

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials

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    Voros, M., Wippermann, S., Gali, A., Gygi, F., Zimanyi, G., & Galli, G. (2014). Exotic phase Si nanoparticles and Si-ZnS nanocomposites: New paradigms to improve the efficiency of MEG solar cells. In 2014 IEEE 40th Photovoltaic Specialist Conference, PVSC 2014 (pp. 3432-3434). [6925670] (2014 IEEE 40th Photovoltaic Specialist Conference, PVSC 2014). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/PVSC.2014.6925670