We offer guaranteed largest undoped or doped Bi2Se3 crystals in the commercial market. Bismuth selenide (Bi2Se3) is a topological insulator crystal belonging to metal chalcogenide material group. Similar to transition metal dichalgonides and graphite, Bi2Se3 is a layered material with weak vdW interlayer coupling. Our Bi2Se3 crystals have been developed at our facilities with topological states, structural crystallinity, reduced defect density, and high purity in mind. They measure ~1cm in size which is the largest size offered in the field. Our crystals exhibit world only 99.9999% purity levels and defect density concentrations as low as 1E9cm-2. Our Bi2Se3 crystals are ideal for electronic, topological insulator, and other solid state sciences research. Examples include scanning tunneling (STM), transmission electron microscopy (TEM), and other spectroscopic studies. Overall, Bi2Se3 displays very sharp and clear Raman modes with FWHM less than 4cm-1, sharp XRD pattern free of minority phases. If your research needs doping in Bi2Se3, we can also incorporate Ca, Nb, Ni, and Au dopants in Bi2Se3 crystals.