Enhanced Performance of Germanium Halide Perovskite Solar Cells through Compositional Engineering

Indira Kopacic, Bastian Friesenbichler, Sebastian Franz Höfler, Birgit Kunert, Harald Plank, Thomas Rath*, Gregor Trimmel

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Germanium halide perovskites are an attractive alternative to lead perovskites because of their well-suited optical properties for photovoltaic applications. However, the power conversion efficiencies of solar cells based on germanium perovskites remained below 0.2% so far, and also, the device stability is an issue. Herein, we show that modifying the chemical composition of the germanium perovskite, i.e., introducing bromide ions into the methylammonium germanium iodide perovskite, leads to a significant improvement of the solar cell performance along with a slight enhancement of the stability of the germanium perovskite. With substitution of 10% of the iodide with bromide, power conversion efficiencies up to 0.57% were obtained in MAGeI2.7Br0.3 based solar cells with a planar p–i–n architecture using PEDOT:PSS as hole and PC70BM as electron transport layer.
Original languageEnglish
Pages (from-to)343-347
Number of pages5
JournalACS Applied Energy Materials
Issue number2
Publication statusPublished - 2018

Fields of Expertise

  • Advanced Materials Science

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