Liquid Phase Epitaxy of IV-VI Topological Crystalline Insulator

Topological Crystalline Insulators (TCIs) have been a valued class of materials in recent years for their ability to form symmetry-protected massless surface states. Liquid Phase Epitaxy (LPE) is a high temperature deposition technique used for growing cost-efficient 2D heterostructures, while still maintaining crystalline quality and low dislocation density. Growth with LPE can become difficult due to high temperature and no vacuum. LPE has been commonly used for the growth of single crystal materials like GaAs, however there is limited work on lead salts like that of the chalcogenides and salt substrates. Here binary chalcogenide thin films have been grown with LPE and compared with more conventional methods like MBE. We found epitaxial lattice matching of binary SnTe on (111) BaF2 substrates, displaying high mobility. These results demonstrate that with specific parameters lead salts of higher thicknesses can be grown via LPE in a non-vacuum setting; implicating the quality of LPE growth vs other more expensive methods. The work thus far on SnTe LPE opens doors towards SnPbTe alloys, GeTe thin films, and even superlattices. Furthermore, highlighting that LPE can contribute to novel alloys and superlattices of lead salts.