Epitaxial Growth of Topological Insulators on Semiconductors (Bi2Se3/Te@Se) toward High-Performance Photodetectors

Heterojunctions, composed of different materials, are widely explored in optoelectronic devices thanks to their unique advantages, such as high carrier mobility and excellent photoelectronic characteristics. In this work, Bi 2 Se 3 /Te@Se heterojunctions (Bi 2 Se 3 /Te@Se) are synthesized through the epitaxial growth of Bi 2 Se 3 nanosheets (Bi 2 Se 3 NTs) on tellurium@selenium nanotubes (Te@Se NTs) by using a low-cost and facile solvothermal process. Bi 2 Se 3 /Te@Se are further applied in high-performance photoelectrochemical (PEC)-type photodetection due to the advantages of broadband optical response and fast carrier relaxation time. The PEC results demonstrate that the as-prepared photodetectors have pronounced photoresponse behavior from the ultraviolet to visible band with self-driven ability and excellent long-term stability. It is anticipated that this work provides a new strategy for epitaxial growth of topological insulators on semiconductors for designing new heterojunctions toward high-performance optoelectronic devices.