在能源發展與環境保護的議題中，太陽能成為現今主流發展的綠色能源之一。為了降低成本及效率的提升，電池表面的抗反射微結構能使入射光反射率降低以達到增加光吸收效率的目的。日前由M. A. Green等人所提出的PERL太陽能電池模組效率達25%，而在此模組中只在入射光側有抗反射金字塔微結構。
目前工業界對於單晶矽太陽能電池表面微結構製程為浸泡式鹼性濕蝕刻，此製程使矽晶圓雙面皆有金字塔微結構，在未來薄晶圓的發展中，存在著製程中晶圓抽離蝕刻溶液因應力造成的破片問題。相較於晶圓兩側皆含有金字塔的微結構，單面微結構更能使電池背部表面電場(Back Surface Field, BSF)在製程上厚度較為均勻且平整，可以避免背部表面電場過薄所導致電子穿隧效應而使電子電洞復合的現象。並在鈍化層薄膜的應用上，平整的表面不僅改善因粗糙結構所造成的膜厚不均勻問題，也改善了載子較容易在粗糙的金字塔微結構上復合的問題。
本研究目的在於利用震盪器霧化蝕刻溶液，將霧滴沉降至晶圓表面進行單面蝕刻，此製程方法簡易且溶液成本較低，在加溫系統中一個小時內即可達到與傳統浸泡式製程相同的低反射率金字塔結構，並驗證了在不同粗糙度表面上的背部表面電場製程，厚度及均勻性的差異，突顯單面蝕刻的重要性。

Development of renewable energy for environmental protection is the most critical issue in recent years, and solar energy is one of the key technologies for the possible solution. In order to reduce costs and improve efficiency of silicon based solar cells, surface texture is implemented to reduce the reflectivity of incident light to enhance the efficiency of light absorption. Recently, M. A. Green has demonstrated the efficiency as high as 25% in PERL solar cell module which has been textured only one side to be pyramid structure.
The standard industrial process for the surface texture in single crystalline silicon based solar cell is alkaline immersion wet etching method. This process creates double-sided pyramid structure in silicon wafer which may give rise to a fragmentation problem caused by the stress due to immersion technique. As compared to the silicon wafer with two-sided pyramid structure, single-sided pyramid structure has advantage in the manufacturing process of the back surface field. Flat structure in BSF side could improve the uniformity in thickness of BSF layer and so that avoid electronic tunnel effect at the thinner BSF layer. Furthermore, the performance of passivation layer can also be benefited from the improvement in the flat structure and uniformity in BSF layer.
In this thesis, we develop the spray etching method to texture single-sided pyramid structure in silicon wafer. This process is a simple and low cost method; it only takes one hour to fabricate the single-sided pyramid structure which has as low reflectivity as that from the traditional immersion process.

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