| Solar energy is an inexhaustible green energy。At present, Crystalline silicon solar cells occupy more than80%of the market, and in a long time in the future will continue to dominate。However, conventional Crystalline silicon solar cells exist process of light attenuation phenomenon in the power generation, which makes the battery conversion efficiency drop by3-5%, and greatly restricts the development of the solar cells。Earlier studies have found that light attenuation phenomenon is associated with boron oxygen complexes in silicon, but so far the essence of the light attenuation defect has not yet been determined。The main content of my thesis:(1) A simple introduction of Crystalline silicon solar cells work principle and preparation technology。(2)The source of raw materials of the preparation of Crystalline silicon solar cells and the impurity elements in raw materials。And introduces the research progress of light attenuation phenomena systematically。(3) Introduce the theory basis of first principles calculation and the three hypotheses, as well as VASP of the first principles calculation software。(4) Here are the key points and innovation points of this thesis, emphasis on the construction of calculation models-N type doping boron interstitial model、N type doping substitutional boron model、type doping interstitial phosphorus model、P type doping substitutional phosphorus model、Boron oxide silicon crystal model. Introduce VASP of the four set parameters and parameter values of the input file in detail. After the relaxation by calculation, we can know the stable structure boron oxygen complexes in the silicon crystal。Thus we can clearly know that the concentration of boron oxygen complexes is proportional to boron concentration or the net boron concentration。We can also determine whether exist B-P pair or not。(5) Summary this paper, after calculation what we get can help future research on boron oxygen complex defects。... |
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