利用合成氧化鋅奈米柱陣列與奈米壓印製作抗反射層並應用於太陽能電池

Abstract

太陽能電池的照光面一般都會有抗反射層來減少入射陽光的反射，以提升太陽能電池的轉換效率。本論文利用兩種不同的製程，形成奈米結構作為抗反射層，以提昇轉換效率。 利用溶液法成長氧化鋅奈米柱陣列，可在基材表面完成大面積、覆蓋性佳的奈米結構。藉由改變反應條件，形成不同表面型態的奈米柱，而在光照射下也有不同的抗反射效果。接著將氧化鋅奈米柱做為抗反射層，成長於矽太陽能電池，能將轉換效率由10.4%提升至12.8%。 此外，我們利用電子束微影以及溼式蝕刻法，在矽基板上形成奈米結構。藉由圖形設計以及蝕刻條件的不同，獲得反射率在全波長低於5%的低反射結構，並且可做為奈米壓印的模板。奈米壓印可將奈米結構簡易、低成本的複製，藉由簡易的奈米壓印機，將模板表面結構轉印至高分子薄膜上，形成低反射率的抗反射薄膜，並且應用於太陽能電池表面。

An efficient antireflection (AR) layer can reduce the light reflection and enhance the solar cell performance. This thesis aims at the fabrication and research of two different kinds of AR layers. In the first part, we investigated solution-grown ZnO nanorod arrays as the AR layer for Si solar cells. The nanorod morphology, controlled through synthetic chemistry, has a great effect on the AR layer performance. We demonstrate that the light harvest efficiency of the solar cells can be greatly improved from 10.4% to 12.8% by using the ZnO nanorod arrays as the AR layer on Si solar cells. In the second part, we fabricated nanostructured Si molds by e-beam lithography and chemical wet etching. The reflectance of the nanostructured mold was lower than 5% throughout the visible light range. The nanostructures on the molds were imprinted on a PMMA layer. The PMMA Layer, which used as the AR layer, was then lift-off and transferred onto a Si solar cell. It provides a simple and low cost mean in a large scale to produce AR layers for improving solar cell performance.