| In21century, the energy crisis and pollution of environment are serious challenges for human being, developing new energy and renewable clean energy is one of the most decisive influence technologies. Among them, solar photovoltaic technology is the fastest developing and the most dynamic renewable technology in recent years. As the second generation solar cell, amorphous silicon thin film solar cell can cut costs of solar cell and becomes the focus of studies. In this thesis, good quality a-Si:H thin film were prepared on the glass substrate by multi-chamber PECVD system, then were applied in amorphous silicon thin film solar cell on stainless steel substrate, in order to improve the efficiency. Research contents and main innovations were described as follow.In the first part, a-Si:H thin film were prepared on glass substrate by vary high frequency plasma enhancement chemical vapor deposition (VHF-PECVD,60.293MHZ). Under the condition that the temperature and distance space between the cathode and anode didn’t change, the influence of factors including silane concentration, total flow rate, pressure and the power were systematically investigated and the following conclusion were obtained.1. Low silane concentration, low pressure, low power were conducive to a-Si:H thin film with low deposition rate and good quality.2.The gas flow rate had a great effect on the defeat density of silicon films. With the gas flow rate increasing, the deposition rate and quality of films would increase. But if the gas flow rate was very high, the gas residence time would be shorter, and the deposition rate, dark conductive, light conductive would decrease.In the second part of the thesis, intrinsic layer with optimized preparation process was applied in a-Si thin film solar (SS/Ag/AZO/n-a-Si/i/p-a-Si/ITO) cell deposited on stainless steel. The influence of factor including the thickness of intrinsic layer, the p-i interface withplasma process, the area of solar cell and back reflector were systematically investigated and the following conclusion were obtained.1. With the deposition time of intrinsic layer increasing, the parameters including quantum efficiency (QE) in optical band among300-800nm, Voc and Jsc increased. When the deposition time of intrinsic layer was2900s, the thickness of intrinsic layer was223.3nm, a-Si:H solar cells with Voc0.96V, FF45.90%, Jsc13.81mA/cm2, Eta6.11%were obtained.2. The pi interface with H2plasma process could improve the quality of thin film solar cells. The quantum efficiency of solar cell in yellow green (560～580mn), yellow (580-595nm), orange light (595～595nm) and red (605～700nm) wavelength of light were significantly improved. The max value increased from84.25%to89.87%. The Voc, Jsc and Eta also increased, from0.95V to0.97V, from12.45mA/cm2to17.43mA/cm2, from5.81%to6.41%.3. The a-Si:H thin film solar cells with0.25cm2were prepared in the same condition. The Jsc didn’t change, because it had nothing to do with the areas of solar cells, only related to the preparation process condition. The FF decreased deeply, this might attribute to the inner resistance increased with the areas. In conclusion, the efficiency of solar cells related to the Voc and FF, and mainly depended on the FF.4. The back reflector of a-Si:H solar cell could improve the QE of light in wavelength of540-800nm, Jsc and Eta. Without the back reflector (SS/n-a-Si/i/p-a-Si/ITO), the efficiency of solar cell decreased from6.23%to5.19%. This might attribute to that the back reflector had a significant influence on the Jsc and FF. This might be important to the light absorption of a-Si/μc-Si tandem cells. |
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