Evidence for topological surface states in epitaxial Bi2Se3 thin film grown by pulsed laser deposition through magneto-transport measurements

• Grown epitaxial Bi2Se3 thin films on Al2O3 (0 0 0 1) substrates by PLD via domain matching epitaxy paradigm.
• Relatively low repetition rate and low deposition temperature are key elements to achieving Bi2Se3 epitaxial films.
• Weak antilocalization and linear magnetoresistance suggest topological surface states in PLD-grown Bi2Se3 films.

We report epitaxial growth via domain matching epitaxy of Bi2Se3 thin films on Al2O3 (0 0 0 1) substrates with over 13% lattice misfit and critical thickness less than one monolayer. X-ray and electron diffraction patterns confirm that the layers are epitaxial with (0 0 0 1) Bi2Se3 || (0 0 0 1) Al2O3 and [21¯1¯0] Bi2Se3 || [21¯1¯0] Al2O3 (or) [21¯1¯0] Bi2Se3 || [112¯0] Al2O3 without the presence of an interfacial pseudomorphic layer. X-ray photoemission spectroscopy reveals that the films are Se-deficient, in agreement with electrical transport data showing n-type carriers and metallic behavior. Magneto-resistance (MR) measurements show a cusp feature corresponding to weak antilocalization and linear-MR shows a non-saturating trend up to 9 T. These results suggest topological surface states in PLD-grown Bi2Se3 films.