Stability of CsNaBiBr and CsNaBiCl.

Bismuth-based halide perovskites are nontoxic alternatives to widely studied lead-based perovskites for optoelectronic applications. Here, we synthesized CsNaBiCl thin films and attempted to synthesize CsNaBiBr using physical vapor deposition. While CsNaBiCl forms a stable cubic structure with a 3.

Stability of the Halide Double Perovskite CsAgInBr.

CsAgInBr is among the lead-free halide perovskites of interest, predicted by first-principles calculations to be stable with a direct band gap, but there has been only one report of its synthesis. Herein we report the formation of CsAgInBr thin films through thermal evaporation of CsBr, AgBr, and InBr and subsequent annealing between 130 °C and 250 °C. CsAgInBr appears stable in this temperature range.

High photoluminescence quantum yield near-infrared emission from a lead-free ytterbium-doped double perovskite.

When excited by photons with energies greater than 2.2 eV, the bandgap energy, Yb-doped CsAgBiBr thin films synthesized physical vapor deposition emit strong near-infrared luminescence centered at ∼1.24 eV the YbF → F electronic transition.

Solution-Processed Bismuth Halide Perovskite Thin Films: Influence of Deposition Conditions and A-Site Alloying on Morphology and Optical Properties.

Bismuth-based halide perovskites have been proposed as a potential nontoxic alternative to lead halide perovskites; however, they have not realized suitable performance. Their poor performance has been attributed to substandard film morphologies and too wide of a band gap for many applications. Herein we used a two-step deposition procedure to convert BiI thin films into ABiI (A = FA, MA, Cs, or Rb), which resulted in a substantial improvement in film morphology, a larger band gap, and greater compositional tunability compared toresults when using aconventional single-step deposition technique.