Synthesis of bismuth selenide nanoplates by solvothermal methods and its stacking optical properties

Bismuth selenide (Bi2Se3) is a novel topological insulator that is promising for broad optical absorption materials on the basis of its large bulk band and well-defined single Dirac cone. Herein, few-layer Bi2Se3 nanoplates of different sizes have been successfully synthesized via the solvothermal method. We present our discovery of optical properties on homojunction Bi2Se3 nano plates with FTIR measurements. The interface of homojunction Bi2Se3 nanoplates demonstrates an interesting optical modulation in the near-infrared region in contrast to individual bulk Bi2Se3 and other reported 2D hetero-structure materials. It was validated that the unexpected behavior was attributed to the interface between variously stacked nanoplates and its unique zero-wave anti-reflection properties. Our experimental results provide evidence of the Bi2Se3 nanoplate possess high optical absorption in the near-infrared range, promising for photothermal and optical diagnostic therapy application.