Quantum size effects and transport properties of Bi 2 (Te 1-x Se x ) 3 3D-topological insulator thin films

In this work, it was established that the room-temperature thickness (d = 16–207 nm) dependences of the Seebeck coefficient, Hall coefficient, and electrical conductivity in n-Bi2(Te0.9Se0.1)3 topological insulator thin films grown on glass substrates, in the thickness range of d = 16–85 nm exhibit an undamped oscillatory behavior with a large amplitude and are well approximated by a harmonic function with a period Δd=(8.0 ± 0.5)nm. The anionic substitution leads to some changes in the quantum size effects manifestation. The experimental results are consistent with theoretical calculations of Δd based on the infinitely deep potential well model. A sustained character of the oscillations is attributed to topologically protected surface states.