Comparative Study of MBE Grown Epitaxial Bi₂Te₃ On Various Standard Substrates

Three dimensional topological insulators (TIs) are materials in which the bulk insulating gap is bridged by highly conducting surface states that are topologically protected [1]. A systematic growth of these materials is a crucial step to investigate fundamental quantum properties in pristine films and for further hetero-structure designs in exploring proximity driven effects [2]. Here, we show high quality epitaxial growth of Bi₂Te₃ on a variety of substrates (sapphire, STO, GaAs and SiO₂) and thereby compare the crucial parameters in terms of film quality such as mobility, carrier concentration etc. The films are analysed by in-situ RHEED, ex-situ XRD, Raman and rigorous electron transport measurements. The growth conditions are optimized to portray surface state dominant characteristics in each sample, observed via weak anti-localization effects; and hence catering to the demands of different substrates for a variety of applications. Magnetic field dependent transport measurements at low temperature exhibit interesting anisotropic effects in the in-plane field configuration, which will be discussed.