以微米球微影技術製備有序矽奈米柱陣列及其光電性質研究

Fabrication of the ordered silicon nanorod array through the microsphere lithography method and investigations on its photovoltaic properties

廖曼伶(Liao-Man Ling)

指導教授 ： 吳振名 ； 戴念華

國立清華大學/工學院/材料科學工程學系/碩士(2012年)

摘要

利用微米球自組裝的特性，於矽基板上旋塗單層排列之PS球，並以電漿轟擊縮小球的尺寸，以此為模板進行金屬輔助化學蝕刻，藉由改變電漿轟擊及浸泡蝕刻溶液的時間，可以精準控制矽奈米柱的直徑與長度。由可見光光譜儀分析其反射率，發現越長的矽奈柱具有越低的反射率，適合作為太陽能電池的抗反射層，然而電化學蝕刻反應在矽奈米柱表面產生許多缺陷，進而限制載子的傳遞。因此，本研究在矽晶片上製備出不同長度及線徑的奈米柱陣列，以旋塗摻雜法進行多次磷擴散，並濺鍍金屬電極組裝成太陽能電池，探討不同微觀結構及載子濃度對太陽電池光電轉換效率的影響。其實驗結果顯示，當矽奈米柱陣列長度800 nm，線徑720 nm時進行兩次磷擴散後組成之電池具有最佳之效率值6.79%，與矽平板太陽能電池比較，約有22%之增幅。

關鍵字

矽奈米柱 ； 太陽能電池 ； 抗反射性質 ； 微米球微影法

並列摘要

To improve anti reflection and enhance the p-n junction of a Si-based solar cell, single-layer polystyrene spheres (PS) were self-assembled onto Si substrates by spin coating followed by plasma treatment for reducing the size of PS spheres. The reduced spheres were used as a template for synthesizing Si nanorods (SiNRs) through the metal-assisted chemical etching process. Using this method, diameter and height of the SiNRs can be accurately controlled. Reflectivity of the silicon nanorods was tested by the UV/vis spectrometer, it is found that longer nanorods are more effective for light trap and absorption, which is applicable as an anti-reflection layer in solar cells. However, the etching process for silicon nanorods will cause surface defects, which limits the carrier transfer. In order to study the effects of SiNR dimension on the performance of Si-based solar cell and measured the conversion efficiency of the solar cell using SiNR array as the antireflection layer, this work fabricated SiNR array with different length and diameter. Phosphorus doping was performed using the spin-on-doping (SOD) technique. According to the results, SiNR solar cell with 720 nm in diameter and 800 nm in length, subjected to phosphorus doping for two times reveals a high performance with an efficiency of 6.79%, which is 22% higher than that of planar one.

並列關鍵字

Si nanorods ； solar cell ； anti-reflection ； microsphere lithography

參考文獻

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