Öffnet in neuem Fenster Opens in a new window Öffnet externe Seite Opens an external site Öffnet externe Seite in neuem Fenster Opens an external site in a new window

Institute Silicon Photovoltaics

NextBase: Next-generation interdigitated back-contacted silicon heterojunction solar cells and modules by design and process innovations

The NextBase project aims at developing innovative high performance c-Si solar cells and modules based on the interdigitated back-contacted silicon heterojunction (IBC-SHJ) solar cell concept.


Sketch of a rear contact a-Si:H/c-Si heterojunction solar cell with interdigitated contacts: Vertical cross section of the cell, and horizontal cross section through the contact layers on the cell’s rear side.


Project goals are solar cells with efficiencies above 26.0% and corresponding solar modules with efficiencies above 22.0%. At the same time, the NextBase project pursues the development of a new industrial manufacturing tool and low-cost processes enabling a competitive IBC-SHJ solar module cost of <0.35 €/Wp.

Within the project, HZB develops both photolithography based (testing & referencing) and laser & screen-printing based (industry compatible) concepts for SHJ cells. Furthermore, new low contact-resistance materials/carrier selective contacts are developed, materials are characterized, and numerical simulations are performed in 1D and 2D.


The project consortium comprises 14 partners from 8 European countries:

  • Forschungszentrum Jülich GmbH, Germany
  • Centre Suisse d’Electronique et de Microtechnique SA, Switzerland
  • Interuniversitair Micro-Electronica Centrum VZW, Belgium
  • Helmholtz-Zentrum Berlin für Materialen und Energie GmbH GmbH (Institutes silicon photovoltaics and PVcomB), Germany
  • Ecole Polytechnique Fédérale de Lausanne, Switzerland
  • Fraunhofer-Institut für Solare Energiesysteme, Germany
  • Technische Universiteit Delft, Netherlands
  • Commissariat à l’énergie atomique et aux énergies alternatives, France
  • Fyzikalni Ustav AV CR V.V.I, Czech Republic
  • Meyer Burger Research AG, Switzerland
  • Enel Green Power, Italy
  • DSM Andvanced Surfaces BV, Netherlands
  • Norwegian Crystals, Norway
  • Uniresearch BV, Netherlands

The NextBase project has received funding from the European Union’s Horizon2020 Programme for research, technological development and demonstration under Grant Agreement no. 727523.