How to tame your bromine: bandgap tuning of solvent-free hybrid perovskites in a vapor transport deposition process
- 1Institute of Electronic Materials and Devices
- 2Leibniz University Hannover
- 3Institute for Solar Energy Research Hamelin ISFH
Abstract
We present a sequential physical vapor and gas phase transport deposition process for batchcapable formation of metal halide perovskite films, applicable to single- and multi-junction solar cells. After evaporating porous Cs-containing Pb halides via physical vapor deposition onto the substrate or bottom cell, we use a quartz furnace to deposit the organic precursor, formamidinium iodide (FAI), onto this inorganic scaffold via vapor transport deposition. Ammonia is used as carrier gas to prevent decomposition of FAI. The resulting perovskite is already present in the photoactive alpha phase. The process time can be minimized down to 15 min, depending on the scaffold, as no subsequent annealing is required. Notably all contacting layers in this work, including self-assembled molecules and passivation, are also fabricated with solvent-free processes. We note an occurring halide exchange reaction between the FAI in vapor phase and Br in the scaffold and present a proposed reaction scheme. By utilizing this reaction, we can vary the resulting bandgap of the perovskite to fit to the requirements for tandem applications, showing a broad process window. The resulting champion cell (1.66 eV) created with this approach reaches 18.3% power conversion efficiency, with a photoluminescence quantum yield of 1.6 % on full cell stacks.
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BibTeX
@misc{clausing2026tame,
title = {{How to tame your bromine: bandgap tuning of solvent-free hybrid perovskites in a vapor transport deposition process}},
author = {Roland Clausing and Joachim Vollbrecht and Verena Barnscheidt and Robby Peibst},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010574/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010574/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - How to tame your bromine: bandgap tuning of solvent-free hybrid perovskites in a vapor transport deposition process
AU - Roland Clausing
AU - Joachim Vollbrecht
AU - Verena Barnscheidt
AU - Robby Peibst
PY - 2026
DA - 2026/10/16
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010574/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010574/v1
AB - We present a sequential physical vapor and gas phase transport deposition process for batchcapable formation of metal halide perovskite films, applicable to single- and multi-junction solar cells. After evaporating porous Cs-containing Pb halides via physical vapor deposition onto the substrate or bottom cell, we use a quartz furnace to deposit the organic precursor, formamidinium iodide (FAI), onto this inorganic scaffold via vapor transport deposition. Ammonia is used as carrier gas to prevent decomposition of FAI. The resulting perovskite is already present in the photoactive alpha phase. The process time can be minimized down to 15 min, depending on the scaffold, as no subsequent annealing is required. Notably all contacting layers in this work, including self-assembled molecules and passivation, are also fabricated with solvent-free processes. We note an occurring halide exchange reaction between the FAI in vapor phase and Br in the scaffold and present a proposed reaction scheme. By utilizing this reaction, we can vary the resulting bandgap of the perovskite to fit to the requirements for tandem applications, showing a broad process window. The resulting champion cell (1.66 eV) created with this approach reaches 18.3% power conversion efficiency, with a photoluminescence quantum yield of 1.6 % on full cell stacks.
ER -