Boron-doped hydrogenated silicon carbide alloys containing silicon nanocrystallites for highly efficient nanocrystalline silicon thin-film solar cells

Ji Eun Lee, Seung Kyu Ahn, Joo Hyung Park, Jinsu Yoo, Kyung Hoon Yoon, Donghwan Kim, Jun Sik Cho

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Boron-doped hydrogenated silicon carbide alloys containing silicon nanocrystallites (p-nc-SiC:H) were prepared using a plasma-enhanced chemical vapor deposition system with a mixture of CH4, SiH4, B2H6 and H2 gases. The influence of hydrogen dilution on the material properties of the p-nc-SiC:H films was investigated, and their roles as window layers in hydrogenated nanocrystalline silicon (nc-Si:H) solar cells were examined. By increasing the RH (H2/SiH4) ratio from 90 to 220, the Si - C bond density in the p-nc-SiC:H films increased from 5.20 × 1019 to 7.07 × 1019/cm3, resulting in a significant increase of the bandgap from 2.09 to 2.23 eV in comparison with the bandgap of 1.95 eV for p-nc-Si:H films. For the films deposited at a high RH ratio, the Si nanocrystallites with a size of 3-15 nm were formed in the amorphous SiC:H matrix. The Si nanocrystallites played an important role in the enhancement of vertical charge transport in the p-nc-SiC:H films, which was verified by conductive atomic force microscopy measurements. When the p-nc-SiC:H films deposited at RH = 220 were applied in the nc-Si:H solar cells, a high conversion efficiency of 8.26% (Voc = 0.53 V, Jsc = 23.98 mA/cm2 and FF = 0.65) was obtained compared to 6.36% (Voc = 0.44 V, Jsc = 21.90 mA/cm2 and FF = 0.66) of the solar cells with reference p-nc-Si:H films. Further enhancement in the cell performance was achieved using p-nc-SiC:H bilayers consisting of highly doped upper layers and low-level doped bottom layers, which led to the increased conversion efficiency of 9.03%.

Original languageEnglish
Pages (from-to)1715-1723
Number of pages9
JournalProgress in Photovoltaics: Research and Applications
Volume23
Issue number12
DOIs
Publication statusPublished - 2015 Dec 1

Keywords

  • conversion efficiency
  • nanocrystallites
  • silicon carbide
  • silicon thin-film
  • solar cell

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Boron-doped hydrogenated silicon carbide alloys containing silicon nanocrystallites for highly efficient nanocrystalline silicon thin-film solar cells'. Together they form a unique fingerprint.

  • Cite this