| The environment-friendly semiconductor material β-FeSi2, with the band gap of 0.83eV-0.87 eV at room temperature, has the high optical absorption coefficient and high theoretical photoelectric conversion efficiency with 16%-23% on theory only less than Silicon. Recently, with the development of semiconductor device, the research of device based on the β-FeSi2 has been rapidly done, such as solar cell and near infrared detector, and so on.In this paper, the fabrication of β-FeSi2 thin film and the solar cell based on this material were studied by the technology of magnetron sputtering. The details are as follows:1. The influence of annealing temperature, annealing time and the thickness of Fe film on the fabrication of β-FeSi2 thin film was studied. On the basis of the results of XRD, to fabricate the β-FeSi2 thin film, the best annealing temperature is 880℃. Under the conditions of 880℃15hours, 880℃18hours, 880℃20hours and 880℃22hours, and the thickness of Fe film 80nm-130 nm, the β-FeSi2 films with a direct gap of about 0.85 eV were fabricated. Compared with the results of Hall Effect, it was found that the β-FeSi2 thin films under the conditions of 880℃18hours and 880℃22hours have better semiconductor properties.2. The β-FeSi2/Si heterojunction and the Si/β-FeSi2/Si double heterojunction were fabricated on the Si substrate, and their electrical and optical properties were analysized. According to the electrical and optical characteristics, it was found that single heterojunction has P-type conductivity and the double heterojunction has N-type conductivity. The thickness of β-FeSi2 thin film increases with the increasing of annealing time with the certain thickness of Fe thin film. The optical absorption efficiency decreases with the increasing of thickness of β-FeSi2 thin film.3. The AMPS-1D software was used to simulate the β-FeSi2 thin film solar cell. It was found that the photoelectric conversion efficiency of β-FeSi2/Si solar cell reached over 10% when the thickness of Si substrate was 1μm. The photoelectric conversion efficiency decreases with the increasing of the thickness of Si substrate. When the thickness of Si substrate was 200μm or 500μm, the photoelectric conversion efficiency of β-FeSi2/Si solar cell was below 1%. When the thickness of Si substrate and doping concentration of β-FeSi2 have the same value, the photoelectric conversion efficiency of β-FeSi2/Si solar cell increases with the increasing of the thickness of β-FeSi2 thin film between 100 nm to 500 nm. Under the condition of the same doping concentration, the solar cell have higher photoelectric conversion efficiency when the Si substrate is thinner. For the double heterojunction solar cell of β-FeSi2, it was found that doping concentration（1016-1019cm-3） had hardly influenced on its efficiency with the ideal value of 24.7% and the thickness of Si layer between 20 nm to 200μm had influenced with less than 1% on its efficiency. The best thickness of β-FeSi2 of the solar cells is 300 nm.The relationship between the absorption layer thickness of β-FeSi2 thin film solar cell and the sun wavelength was studied, and the corresponding formula was obtained. The best thickness of β-FeSi2 thin film is between 200 nm to 250 nm.4. Using the technology of magnetron sputtering, the solar cells of β-FeSi2/Si and Si/β-FeSi2/Si were fabricated and the elements of Mn and B were used to change the conductivity and carrier concentration of β-FeSi2/Si. The ohmic electrodes were fabricated by the technology of magnetron sputtering and the screen printing respectively. To obtain Ag front electrode and Al back electrode, the best annealing temperature and time are 650℃15minutes and 450℃20minutes, respectively. For the Si/β-FeSi2/Si heterojunction cell obtained from the experiments, the thickness of Si layer between 25 nm to 300 nm had lower influence on the efficiency of the solar cell and the thickness value of Si film was usually 100 nm. The I-V characteristic of the solar cells with the elements of Mn and B used in β-FeSi2 film was greatly improved.Using the technology of magnetron sputtering, the solar cells of β-FeSi2/Si and Si/β-FeSi2/Si were fabricated and the elements of Mn and B were used to change the conductivity type of β-FeSi2 and increase carrier concentration of β-FeSi2/Si. After doping Mn, β-FeSi2 thin film was P-type conductivity, and after doping B, β-FeSi2 thin film was P-type conductivity. The ohmic electrodes were fabricated by the technology of magnetron sputtering and the screen printing respectively. To obtain Ag front electrode and Al back electrode, the best annealing temperature and time were 650℃15minutes and 450℃20minutes, respectively. For the Si/β-FeSi2/Si heterojunction cell obtained from the experiments, the thickness of Si layer between 25 nm to 300 nm had lower influence on the efficiency of the solar cell.These experimental results are agreement with the simulated results.5. The best I-V characteristic among the β-FeSi2/Si solar cells is Vocmax=0.38 V, Iscmax=0.9mA, ηmax=0.0066%, FFmax=61%, and the best I-V characteristic among the Si/β-FeSi2/Si solar cells is Vocmax=0.4V, Iscmax=0.754 mA, ηmax=0.0076%, FFmax=61%。...
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