Interdigitated back‐contacted structure: A different approach towards high‐efficiency ultrathin copper indium gallium (di) selenide solar cells.

1. Nasim Rezaei, Paul Procel, Marcel Simor, Zeger Vroon, Miro Zeman, Olindo Isabella (2020)
Progress in Photovoltaics: Research and Applications (2020) 3296.

An interdigitated back-contacted (IBC) configuration is proposed for submicron cop-per indium gallium (di)selenide (CIGS). In a modelling platform, the structure wasopto-electrically optimized for maximum efficiency. The results are compared with areference front/back-contacted (FBC) solar cell with similar absorber thickness andexhibiting 11.9% efficiency. The electrical passivation at the front side is accom-plished by an Al2O3layer, which is endowed with negative fixed charges. The resultsindicate that with an optimal geometry and engineered bandgap grading, the effi-ciency of the new IBC structure can reach 17%. Additionally, with a reasonably lowdefect density in the absorber layer, efficiencies as high as 19.7% and open-circuitvoltage comparable with that of the record solar cell are possible with the IBCstructure.

Progress in Photovoltaics – 2020 – Rezaei – Interdigitated back‐contacted structure A different approach towards