Molecular beam epitaxial (MBE) growth method of Bi element regulated and controlled GaAs-based nanowire crystal structure

Abstract

The invention discloses a molecular beam epitaxial (MBE) growth method of a Bi element regulated and controlled GaAs-based nanowire crystal structure. A Bi element is introduced as an activating agent during the growing process of nanowires in an MBE growth chamber, the ionicity of GaAs is reduced, and the formation of a nanowire zinc blende structure is promoted. The method is characterized in that the Bi evaporator source temperature is regulated during the process of nanowire growth according to the beam equivalent partial pressure of a Ga element so as to control the beam equivalent partial pressure of the Bi element and to ensure that the ratio of the beam equivalent partial pressure of the Bi element to that of the Ga element is x, and the value of x can influence the regulating and controlling ability of the Bi element to the nanowire crystal structure and influence the feature and the phase structure purity of the nanowires. The method has the benefits that the growth of the GaAs-bases nanowires with the zinc blende crystal structure can be easily realized without changing the growth process conditions of MBE, and thus the method is beneficial to the controlled growth of the GaAs-based nanowires with the wurtzite and zinc blende structure and the formation of a homogeneous heterophase heterogeneous structure of the nanowires, and provides an excellent material for preparing nanoscale photoelectronic devices.

Description

Technical field [0001] The invention belongs to the technical field of nano new material growth, and particularly relates to a molecular beam epitaxial growth method for regulating the crystal structure of GaAs-based nanowires with Bi elements. It is achieved by introducing Bi element in the MBE growth chamber to grow GaAs-based nanowires with wurtzite structure and sphalerite structure coexisting under the conditions of constant growth conditions, that is, growth temperature and V-III beam ratio. technical background [0002] In recent years, one-dimensional semiconductor nanowires have become a new generation of materials for the preparation of nano-level optoelectronic devices due to their excellent performance in electricity, optics, mechanics, and heat. The III-V semiconductors represented by gallium arsenide GaAs have the characteristics of direct band gap, high electron mobility, and low effective mass, and the optoelectronic devices based on III-V semiconductor materials ...

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Problems solved by technology

[0003] However, the crystal structure of GaAs-based nanowires grown by the gas-liquid-solid growth method in MBE mainly exhibits a wurtzite structure; although GaAs-based nanowires with a sphalerite structure can be grown by adjusting the growth process parameters, at this time The growth process conditions are already at the edge of the GaAs-based nanowire growth process window, which is not conducive to the growth of upright nanowires with uniform length and thickness, which will seriously affect the performance uniformity of the prepared GaAs-based nanowire optoelectronic devices

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