Bismuth Selenide Telluride (Bi?Se?.?Te?.?) is developed at our facilities. Selenium to tellurium ratio is fixed at 50-50% [Bi2Se3(1-x)Te3x x=0.5] Topological insulator is a new class of material, in which its bulk is insulating while its surface states are conducting. The surface states of topological insulator are robust against any external perturbation because such states are protected by time-reversal symmetry. Similar to transition metal dichalgonides and graphite, Bi?Se?.?Te?.? is also layered material with weak interlayer coupling. Our crystals are develop in our laboratories last year and has been perfected to provide you with the best quality and reliability. Crystals are easy to exfoliate and get down to single layer unit cell thickness. The order also comes with detailed exfoliation technique allowing you to boost exfoliation rate.