Centimeter size BiSeI crystal grown by physical vapor transport method

On the purpose to get large sized BiSeI crystals for diverse applications based on its physical properties, such as thermoelectric, photoelectric and ferroelectric, etc. We developed a synthesis process to obtain pure BiSeI polycrystal, which was used as source material for further physical vapor transport (PVT) growth of BiSeI single crystal. Strip-shaped BiSeI single crystal with the size of ∼80 × 4 × 0.5 mm ³ was obtained. Needle-like and layered microstructures with homogeneous composition were observed in BiSeI crystal by the SEM. The band-gap of as-grown BiSeI crystal was estimated to be ∼1.29 eV according to the UV–Vis diffuse reflectance spectra. Hall measurement shows that BiSeI single crystal is n-type conductivity with the anisotropic resistivity of 39.3, 3.4, and 1650.4 Ω·cm along a-, b- and c-axis, respectively.