Effects of Laser Annealing on Characteristics of Silicon Heterojunction Solar Cells

• Main Authors: Meng-Shen Wan, 萬孟昇
• Other Authors: 武東星
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/50580546100770227663

碩士 === 國立中興大學 === 精密工程學系所 === 96 === The heterojunction solar cell based on silicon (Si) is one of the new wafer-type structures for photovoltaic application, which features the stability and high efficiency of single-crystalline or polycrystalline Si solar cells. The lower process temperature is another advantage of the Si heterojunction solar cell as compared with that used for the bulk Si wafer one. Therefore, this research topic has been received intensive attention in recent years. In this thesis, the U.S patents related to the Si heterojunction solar cells have been analyzed to understand the latest technique and development, so as to create a new process with low cost and high efficiency. In our experiments, the hot-wire chemical vapor deposition (CVD) was adopted to deposit μc-Si:H/c-Si heterojunction layer, and the Nd-YAG laser was applied to proceed annealing toward emitter layer with different laser power levels, in that, to re-crystallize the micro-crystal Si. The quality of Si films and the conversion efficiency of components can be improved effectively. After that, the different laser powers have been used to anneal to improve the ohmic contact characteristics between the electrode and emitter layer. The obtained results emphasize that the conversion efficiency can be actually increased by applied the laser annealing technique to μc-Si:H/c-Si heterojunction solar cell. The short-circuit current density and fill factor of components were increased after laser annealing. After optimizing the process parameters, the study resulted in a conversion efficiency 12.47 %, fill factor of 0.67, short-circuit current density of 30.53 mA/cm2, and open circuit voltage of 0.613 volt. Therefore, the laser annealing technique is expected to achieve high efficiency Si heterojunction solar cells in the future.