CVD Growth of Bi$_2$Se$_3$ Crystals

We have studied condition for CVD Bi$_2$Se$_3$ growth in detail. Morphology of grown crystal varied drastically depending on temperature of substrate, flow rate of transport gas, temperature of source materials and catalysts. At an optimum condition we could obtain thin single crystals which were hexagonal in shape. At lower temperatures, we have obtained thin wire single crystals. Magneto transport measurement indicated signature of weak anti-localization. Carrier mobility was as large as 2700 cm$^2$/Vs, however two-dimensional carrier density was significantly large $\sim$3.6$\times$10$^{13}$ cm$^{-2}$ possibly due to vacancy of Se atoms.