Magneto-Transport Studies on Single Crystals of Bi1.5Sb0.5Te1.7Se1.3 Topological Insulator

Electrical resistivity measurements on single crystals of Bi1.5Sb0.5Te1.7Se1.3 are reported. Temperature dependence of resistivity shows a metallic behaviour for flakes of 500 pm thickness whereas thinner flakes of 150 pm show an upturn at lower temperatures indicating suppression of bulk defects and revelation of intrinsic bulk semiconducting nature. Magneto-transport measurements also show 2D quantum interference signatures in the form of Weak anti-localization cusp in the low-field and low temperature range. The WAL cusp has been fitted with HikamiLarkin-Nagaoka equation to obtain phase coherence length. Non-linear Hall data indicates the presence of multiple transport channels and the majority carriers are found to be holes.