銀奈米線薄膜電極於光伏元件之應用

Abstract

我們成功的利用了銀奈米線(silver nanowires, agnw) 搭配旋塗製程製作了大面積的透明導電薄膜並做為上電極應用在有機-非有機異質接面混合式太陽能電池上。 目前我們經過最佳化的銀奈米線透明導電薄膜有著寬頻譜 (400nm ~ 2600 nm)大約85%的高穿透率以及低於50Ω/□的片電阻，與一般常用的氧化銦錫(ITO)薄膜相比，已經是相當接近了，但在製程成本方面，由於銀奈米線薄膜皆為溶液製程，相較於氧化銦錫的電漿濺鍍製程，無論是在材料消耗以及製程成本上都是有大幅下降的趨勢。並且我們利用了銀奈米線薄膜做為前電極，製作了面積為1平方公分的有機-非有機異質接面混合式太陽能電池，並且有10.49%的高光電轉換效率(PCE)以及72%的填充因子(FF)，相較於使用銀金屬梳狀電極的樣品，有著236.9%以及243%的增益。 本篇論文的第一部分將會討論如何利用含有銅元素鹽類輔助的多元醇還原法，快速且低成本的製作適合的一維奈米銀線結構. 接著則是將銀奈米線均勻的塗佈至玻璃基板上以量測銀奈米線薄膜的各種光電特性，並且我們也嘗試了一些關於改善銀奈米線薄膜導電性的方法來使銀奈米線薄膜成為高品質的透明導電薄膜。最後我們將銀奈米線薄膜應用至有機-非有機異質接面混合式太陽能電池做為前電極，比較了在不同基板形貌下銀奈米線薄膜與PEDOT:PSS層的接觸情形對於整體光電轉換效率以及填充因子的影響。 並且我們優化了整個製程且搭配矽奈米線結構的基板製作出了高效率的異質接面混合式太陽能電池做為證實銀奈米線薄膜應用於光伏元件上的除了成本之外也可提升效率的優勢。

We have successfully fabricated large-area silver nanowire (Agnw) transparent conductive thin film using a spin coating process and apply it to the organic-inorganic hetrojunction hybrid solar cells as the frontal electrode. The optimized Agnw thin film has a broadband high transmittance of 85% and low sheet resistance of 50Ω/□ which is comparable to commercial indium tin oxide (ITO) thin film with a low fabrication cost. The 1cm×1cm hybrid solar cells employing Agnw thin film electrode show high power conversion efficiency (PCE) and fill factor of 10.49% and 72% respectively, corresponding to 236.9% and 243% enhancement to reference sample with silver grid electrode. In the first section of this thesis, I describe how to fabricate the silver nanowires by means of a Cu-containing salt-mediated polyol process which is rapid and low cost fabrication process. Next I introduce the spin coating method and the measurements of transmittance and sheet resistance for the optimization of the Agnw thin film. The improvement of Agnw thin film electrical properties of would also be discussed. Finally, we fabricated hetrojunction organic-inorganic hybrid solar cell with Agnw thin film as the frontal electrode to demonstrate the benefits for photovoltaic device. We also observe that substrate surface morphology is highly related to device performance with Agnw thin film electrode.