Back-contacted silicon heterojunction solar cells with efficiency >21%

Andrea Tomasi, Bertrand Paviet-Salomon, Damien Lachenal, Silvia Martin De Nicolas, Antoine Descoeudres, Jonas Geissbühler, Stefaan De Wolf, Christophe Ballif

Research output: Contribution to journalArticlepeer-review

68 Scopus citations


We report on the fabrication of back-contacted silicon heterojunction solar cells with conversion efficiencies above 21%. Our process technology relies solely on simple and size-scalable patterning methods, with no high-temperature steps. Using in situ shadow masks, doped hydrogenated amorphous silicon layers are patterned into two interdigitated combs. Transparent conductive oxide and metal layers, forming the back electrodes, are patterned by hot melt inkjet printing. With this process, we obtain high short-circuit current densities close to 40 mA/cm2 and open-circuit voltages exceeding 720 mV, leading to a conversion efficiency of 21.5%. However, moderate fill factor values limit our current device efficiencies. Unhindered carrier transport through both heterocontact layer stacks, as well as higher passivation quality over the minority carrier-injection range relevant for solar cell operation, are identified as key factors for improved fill factor values and device performance.

Original languageEnglish (US)
Article number6815659
Pages (from-to)1046-1054
Number of pages9
JournalIEEE Journal of Photovoltaics
Issue number4
StatePublished - Jul 2014
Externally publishedYes


  • Amorphous silicon
  • crystalline silicon (c-Si)
  • heterojunctions
  • photovoltaic cells
  • solar cells

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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