次波長抗反射結構製作增進太陽能電池光電轉換效率

Fabrication of sub-wavelength antireflective structure to improve efficiency of photoelectric solar cells

李冠道(Kuan-Tao Li)

指導教授 ： 李有璋

中原大學/工學院/機械工程研究所/碩士(2015年)

https://doi.org/10.6840/cycu201500769

摘要

目前普及的太陽電池發電成本仍過高,效果也並不理想,而在太 陽能電池製作過程中,電池表面的反射率是決定光電轉換效率的重要 關鍵。當太陽光入射於太陽能電池表面時,會因為空氣與材料間的折 射率差異產生了菲涅爾損耗,而影響到太陽能電池的光電轉換效率。 次波長結構抗反射比傳統的抗反射薄膜能有夠好的抗反射效果,能有 效抑制波長的範圍。
本論文利用聚苯乙烯奈米球微影製作不同次波長結構於 6 吋矽 晶太陽能電池表面,而目的是為了提升太陽能電池,首先以有限時域 差分法模擬矽晶太陽能電池基板上不同次波長結構對反射率的影響, 並實際利用 800 nm 聚苯乙烯奈米球鋪陳於 6 吋矽晶太陽能電池基板, 搭配高密度電漿(HDP)蝕刻系統製作反射率極低的子彈狀複合結構, 在量測波長範圍 400 nm~1000 nm 的平均反射率有 0.27%,最後將實 際製作成太陽能電池,在太陽光模擬量測下也有 12.26%的光電轉換 效率。

關鍵字

太陽能電池 ； 抗反射 ； 次波長結構 ； 膠體微影 ； 有限時域差分法

並列摘要

The reflectance between the semiconductor material and air, i.e. Fresnel loss, is one of the main issues to influence the optical-electrical conversion efficiency for the photovoltaic (PV) solar cells. Anti-reflective (AR) thin films are often used to reduce the reflectance for the current manufacturing in the industry. In this study, better AR sub-wavelength structures (SWSs) were sued to understand the influence of various shapes of SWS on the anti-reflectance.
To calculate anti-reflection performance Finite difference time domain (FDTD) method was employed to simulate the reflectance of various shapes of SWSs (cone, paraboloid, and bullet). Polystyrene (PS) spheres (800 nm in diameter) were uniformly spayed onto the 6” polycrystalline silicon wafer to act as an etching mask during the dry etching process. The silicon substrate and PS sphere array were subjected to High density plasma (HDP) etching to fabricate SWS.
The average reflectance of cone, paraboloid, and bullet SWSs were 7.2%, 9.0%, and 2.7%, respectively across a spectral range of 300 nm – 1200 nm. The average reflectance of bullet SWSs with nano tips was only 0.27%. Following the etching process, solar cell manufacturing process was introduced to the silicon wafers with SWSs. The conversion efficiency of cone SWSs is 9.14%, and the efficiency was improved to 12.26% for bullet SWSs with nano tips.

並列關鍵字

Solar cells ； Antireflection ； Subwavelength structures ； Nanospheres lithography ； FDTD method

參考文獻

應研究及規則有序矽單晶奈米結構陣列之製備”,國立中央大學

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