AgBiP₂Se₆ (Silver Bismuth Selenophosphate)

AgBiP₂Se₆ is a layered van der Waals ferroelectric semiconductor crystallizing in the R3̄ space group, with lattice parameters a = b = 6.611 Å and c = 39.697 Å. Its structure consists of covalent [P₂Se₆]⁴⁻ anionic frameworks together with Ag⁺ and Bi³⁺ cations residing in Se-coordinated octahedra, with adjacent layers held together by van der Waals forces; the antiparallel off-centering displacements of Ag⁺ and Bi³⁺ give rise to a compensated ferrielectric configuration and an out-of-plane spontaneous polarization. The material is intrinsically an indirect-bandgap semiconductor, yet multilayer samples exhibit a quasi-direct band structure, with indirect and direct transition energies of approximately 1.46 eV and 1.535 eV at 300 K; their small energy separation gives rise to pronounced photoluminescence.

　　Owing to its visible-range band gap, coupled ionic–electronic transport, and high sensitivity to external stimuli, AgBiP₂Se₆ shows strong potential for optoelectronic conversion, ferroelectric photovoltaics, photodetection, and pressure-tunable optoelectronics, serving as an important platform for exploring structure–property relationships in low-dimensional ferroelectric semiconductors.

　　Sample specifications: Individual crystals measure approximately 3–4 mm,with a purity of up to 99.9999% (6N), with each package containing 2–3 pieces.