High density micro-pyramids with silicon nanowire array for photovoltaic applications

Tasmiat Rahman*, Miguel Navarro-Cia, Kristel Fobelets

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)
196 Downloads (Pure)


We use a metal assisted chemical etch process to fabricate silicon nanowire arrays (SiNWAs) onto a dense periodic array of pyramids that are formed using an alkaline etch masked with an oxide layer. The hybrid micro-nano structure acts as an anti-reflective coating with experimental reflectivity below 1% over the visible and near-infrared spectral regions. This represents an improvement of up to 11 and 14 times compared to the pyramid array and SiNWAs on bulk, respectively. In addition to the experimental work, we optically simulate the hybrid structure using a commercial finite difference time domain package. The results of the optical simulations support our experimental work, illustrating a reduced reflectivity in the hybrid structure. The nanowire array increases the absorbed carrier density within the pyramid by providing a guided transition of the refractive index along the light path from air into the silicon. Furthermore, electrical simulations which take into account surface and Auger recombination show an efficiency increase for the hybrid structure of 56% over bulk, 11% over pyramid array and 8.5% over SiNWAs.

Original languageEnglish
Article number485202
Issue number48
Early online date10 Nov 2014
Publication statusPublished - 5 Dec 2014


  • FDTD
  • nanofabrication
  • optics
  • photovoltaic
  • pyramids
  • SiNWA

ASJC Scopus subject areas

  • Bioengineering
  • General Chemistry
  • Electrical and Electronic Engineering
  • Mechanical Engineering
  • Mechanics of Materials
  • General Materials Science


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