Texturing & surface characterisation of photovoltaic wafers

• Main Author: Ng, Chee Hong.
• Other Authors: David Lee Butler
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/53999
• Institution: Nanyang Technological University

Solar energy is an emerging alternative to fossil fuel. Photovoltaic (PV) cells produce electricity by converting absorbed solar radiation. Hence, there are many on-going studies aimed to improve the efficiency of Photovoltaic cells. Silicon wafer is the key materials in the Photovoltaic (PV) cells. Pyramid like microscopic structures (silicon oxide’s structures after chemical etching is done) on the surface of the silicon wafer are produced by chemical etching and the gradient of these pyramids are crucial parameter in terms of light trapping capability [1]. By optimizing the gradient of these structures, highly efficient Photovoltaic cells can be fabricated. In this project, experiment and analysis were conducted to investigate the correlation of reflectance to the gradient of silicon wafer microscopic structures, together with the relationship of the surface roughness and tensile strength of silicon wafer were studied. The results suggest that reflectance percentage does not solely depend on slope parameter and surface roughness; there might be other factors that could have influence on reflectance. Additionally, the results concluded that there was no strong trend that indicates the correlation of reflectance to hybrid roughness parameter Δa and Sdq silicon wafers. In spite of this, optimal reflectance to flexural strength ratio can be obtained by altering the ratio of chemical in the etching solution and etching time.