Thermodynamic constraints and substrate influences on the growth of high-quality Bi₂Te₃ thin films by pulsed laser deposition

Abstract

We investigated the growth of Bi2Te3 thin films on (111) CaF2 and (111) BaF2 substrates by pulsed laser deposition. Stoichiometric Bi2Te3 thin films were grown using targets with excess tellurium. We adopted a combinatorial temperature variation principle, where the growth temperature is monotonically varied during the growth. This growth method is supportive to effectively minimize Te loss in the Bi2Te3 films. We found large differences in growth conditions between Bi2Te3 thin films on the CaF2 and BaF2 substrates. The lattice matched (111) BaF2 substrate is preferred to grow Bi2Te3 for the further development of topological electronics.