Preparation of two-dimensional atomic crystal nanofilm of bismuth selenide of a large area

Abstract

A synthesis of bismuth selenide with a thickness of 3-4 nm on the surface of mica taken as a matrix was investigated using the gas-solid mechanism. Since discovery of two-dimensional atomic crystals of graphene in 2004, scientists have grown interested in exploring methods for synthesis of two-dimensional atomic crystal nanofilms. Among them, of particular interest are sulfides and transition metal selenides, such as molybdenum sulfide, tungsten selenide, bismuth selenide. Bismuth selenide possesses special thermoelectric, photoelectric properties, therefore there are wide possibilities for its use in such areas as thermoelectric devices, photosensitive elements, optical information keepers, etc. In this connection, there are many studies on the search for optimal methods for the synthesis of bismuth selenide. Each of the proposed methods has its own advantages and disadvantages. In the article, a variety of the recently used gas-liquid-solid mechanism (V-L-S) is used as a method for the synthesis of bismuth selenide. When using amorphous silicon dioxide as a matrix, the synthesized bismuth selenide is not uniform, and the synthesis process is uncontrollable. Therefore, in the work fluorinated gold mica was used as a matrix. The effect of temperature, gas feed rate on the size, shape and thickness of the film was investigated.