English

Fe-doping-induced band structure modification and cryogenic phase stability in Cs2AgBiBr6 single crystals

Materials Science 2026-07-26 v1

Abstract

Despite its promise as a lead-free alternative, the practical application of Cs2AgBiBr6 in optoelectronics is limited by its wide band gap and detrimental intrinsic defects. To overcome these challenges, we synthesized Cs2AgBi0.5Fe0.5Br6 single crystals via a modified hydrothermal method. While both pristine and Fe-doped crystals undergo a structural phase transition near 125 K, Fe incorporation fundamentally alters its impact. The dopant simultaneously narrows the band gap in the high-temperature phase and suppresses the associated cryogenic structural instability. Our optical and X-ray structural studies establish Fe doping as a powerful strategy for tailoring the properties of Cs2AgBiBr6 , advancing its potential for high-performance, low-temperature optoelectronic and spintronic devices.

Cite

@article{arxiv.2607.23456,
  title  = {Fe-doping-induced band structure modification and cryogenic phase stability in Cs2AgBiBr6 single crystals},
  author = {Yanan Li and Xuejiao Wu and Jidong Deng and Jinbao Zhang},
  journal= {arXiv preprint arXiv:2607.23456},
  year   = {2026}
}