ANR project

High Efficiency Epitaxial Tandem Cells CIGS-Silicon

Dates:
October 2020 – May 2024

Project coordinator:
Fonctions Optiques pour les Technologies de l’informatiON (FOTON Rennes)

Partner laboratories :

  • IMN
  • RIBER Bezons
  • Ile-de-France Photovoltaic Institute (UMR-IPVF Palaiseau)
  • Institute for Nanotechnologies (INL Lyon)

IMN staff involved:
Nicolas BARREAU, Eric GAUTRON

PV is growing fast and becoming one of the main pillars of the energy transition. The 30% efficiency target (roadmap published by COP21, initiated by IPVF and named “30-30-30”) will not be achieved with conventional solar cells based on simple junctions. Tandem junctions could theoretically reach 43% by combining a lower VIS/NIR cell, made of single-crystal Si, with an upper cell absorbing the blue/UV part of the solar spectrum, which could be made of CIGS and specially optimized with a gap of around 1.7 eV. We propose an innovative approach based on the use of wide-gap III-V intermediate epitaxial layers (GaP-based) between Si and CIGS. We expect the epitaxial structures (CIGS/III-V/Substrate Si) prepared in this project to reach 18% at 1.7 eV. Tandem cells (CIGS/III-V/Si/Si substrate) with two terminals and 25% efficiency are proposed at the end of the project.