Tuning chemical potential in the dirac cone by compositional engineering

• Published in: AIP advances Vol. 7; no. 10; pp. 105112 - 105112-9
• Main Authors: Gopal, R. K., Singh, Sourabh, Sarkar, Jit, Mitra, Chiranjib
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 01.10.2017; AIP Publishing LLC
• Subjects: Ablation; Bismuth tellurides; Chemical potential; Organic chemistry; Pulsed laser deposition; Pulsed lasers; Temperature dependence; Thin films; Topological insulators; Transport; X-ray diffraction
• ISSN: 2158-3226; 2158-3226
• DOI: 10.1063/1.4999254

To realize fully topological transport for any device applications it is essential to tune the chemical potential in the bulk gap of the Dirac cone. Bi2Se3 (BS) and Bi2Te3 (BT) thin films do not show in general topological transport as the chemical potential doesn’t lie entirely in the bulk gap. We report the successful formation of bulk insulating ternary topological insulators Bi2Se2Te (BST) by double target pulsed laser deposition technique. The films were deposited with sequential ablation of separate BS and BT targets. From the X-ray diffraction analysis and temperature dependent resistivity, we were able to conclude that the as-grown thin films have ordered chalcogen layers and the chemical potential in these thin films lie in the bulk gap. We have been able to achieve this fully topological transport in our sample grown by this technique. Our Magnetotransport data exhibits pronounced two-dimensional weak-antilocalization behavior (WAL) at low temperatures. It was possible to tune the chemical potential at will in the gap by depositing thin films through pulsed laser deposition technique using this simple and cost effective double target approach to grow quaternary TI thin films.