| Mg2Si is a semiconductor material having an indirect band gap, and it has a great reserve of raw materials, which is environmentally friendly and has highly application prospect. and Its absorption band edge is located at around 0.74eV (approximately 1600nm wavelength), and its light absorption coefficient is as high as 104/cm at around 1.3um, more than two orders of magnitude higher than the crystalline silicon. therefore only a few hundred nanometers in thickness can be achieved on sunlight fully absorb near-infrared bands. Then the implementation of this issue, laying a solid theoretical and experimental basis for the development of thin film solar cell and opening up a new way for our country independent research and development of low cost, sustainable and environmentally friendly thin-film batteries, has important economic value of environmental protection and the social efficiency.The thin film of Mg2Si was preparated by the use of exogenous plasma sputtering (HiTUS) in this paper. And this kind of thin films was deposited using a plasma beam bombarding Mg/Si combination of target in the system.Film samples prepared were characterized by a series of performance. The thickness of the thin films was measured with level meter. Crystallography analysis on the thin films was carried out by X ray diffraction (XRD). Microscopic morphology of thin film surface was observated with field emission scanning electron microscope (FESEM). Variation of element valence on the thin film surface was characterized using X-ray photoelectron spectroscopy (XPS). The mechanical behavior of thin film was researched with nano-indentation. The optical performance of thin film was characterized using UV-Vis. characterize The electrical properties of the thin film using the hall test system following conclusions could be withdrawn.1. The deposition rate of Mg and Si were studied at different sputtering process parameters, and the Mg/Si area ratio on the combination of target material was determined through a series of experiments. when the Mg/Si area ratio is 1/2.5, thin film of Mg2Si can be prepared conforming to the stoichiometric ratio.2. Crystallization and properties of thin films are changed front and rear heat treatment, and the sedimentary state thin films are amorphous. The films have taken place in different degree of crystallization after heat treatment. When annealing temperature is 500℃, the degree of film crystallization is better, and only Mg2Si phase is generated. And the average effective hardness of thin film samples is up to 12GPa, elastic modulus of thin film samples is up to 168GPa. The light absorption coefficient of the thin film sample after heat treatment is up to 104 or so. It is found that film absorption edge after heating has a substantial red-shift using ultraviolet-visible absorption spectrum of films through further study before and after heat treatment. When the heat treatment temperature is 500℃, the width of band gap of thin films is 0.76ev, and the conductive type is N-type, the resistivity up to 16Ω·cm, carrier concentration up to 1016cm-3, the hall mobility up to 17.2cm2/V·s. |
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