Controlled vapor phase epitaxial growth of high quality Bi2Se3 thin films and their photoresponse studies

Abstract

Topological insulators are foreseen to offer promising applications in next generation electronic and optoelectronic devices. However, this is said to be tedious without understanding the underlying factors governing the fabrication and physicochemical properties of high-quality topological insulators. In this regard, this article reports on the two-dimensional (2D) growth of high quality Bi2Se3 thin films layered on sapphire by vapor phase epitaxy (VPE). The crystalline rhombohedral phase of the films was substantiated using X-ray diffraction results. The homogeneous distribution of Bi2Se3 thin films were approved through the microscopic images. The high quality in Bi2Se3 was examined through the selected area diffraction patterns and lattice fringes recorded using transmission electron microscopy. Finally, an infrared photo switching device was fabricated using the thin films processed in this work. The device responded linearly in accordance to the intensity of the laser irradiation subjected. The fabricated thin film based device also presented a high reliability through the lack of any degradation in its performance after consecutive switching cycles. Finally, we would like to augment with the fact that the findings observed this work could assist in opening up the possibility for novel optoelectronic applications using Bi2Se3 thin films.