Thermodynamic constraints and substrate influences on the growth of high-quality Bi 2 Te 3 thin films by pulsed laser deposition

We investigated the growth of Bi 2 Te 3 thin films on (111) CaF 2 and (111) BaF 2 substrates by pulsed laser deposition. Stoichiometric Bi 2 Te 3 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 Bi 2 Te 3 films. We found large differences in growth conditions between Bi 2 Te 3 thin films on the CaF 2 and BaF 2 substrates. The lattice matched (111) BaF 2 substrate is preferred to grow Bi 2 Te 3 for the further development of topological electronics.