本論文主要研究製作於亞醯胺基板之可繞式銅銦鎵硒太陽能電池之背電極可靠度，其中專注於研究外加應力所導致之可靠度議題，並提出利用銀奈米線增加背電極可靠度之新穎應用。實驗內容可細分為三部分：首先，我們以改善製程方法降低製程溫度所導致之內應力，以解決傳統鉬金屬背電極表面因製程所導致之裂紋；第二部分，傳統鉬金屬與參有銀或鋁金屬之背電極結構將被製造，並施以自行設計之彎曲測試，以評估其可繞性與可靠度；最後，我們實現了具有優良導電性且無裂紋的銀奈米線鑲嵌之鉬金屬背電極結構，並經由彎曲測試顯示其具有優良的可繞性與可靠度。

　　第一部分研究包含：降低製程升溫速率、在基板的正面與背面鍍上相同厚度之鉬金屬使其承受支應力均衡、與加入熱退火前處理製程。然而，即使製程升溫速率由每分鐘25 ⁰C降至5 ⁰C對薄膜裂紋並沒有顯著改善；在平衡應力之實驗中，基板背面之鉬薄膜雖然改善了製程所導致的基板彎曲，但對薄膜裂紋並沒有幫助；硒化製程前，我們嘗試加入390 ⁰C的鉬薄膜熱退火製程，並成功的解決了鉬薄膜裂紋的問題，但此實驗並不具有再現性；雖然薄膜裂紋之問題並沒有因此被解決，但此實驗指出：熱退火前處理可有效地改善鉬薄膜的品質與釋放後續製程所導致之應力。

　　在第二部分的研究中，我們利用(1)共濺鍍法製作了鋁鉬、銀鉬合金背電極; (2)分別濺鍍鋁、鉬與銀、鉬金屬製作雙層結構之背電極，並施以第一部分實驗中所使用之熱退火前處理，以探討其可繞性與可靠度改善之情況。同時，我們設計了可定量外加應力與可繞度的彎曲測試，並以此測試評估合金背電極與雙層結構背電極之特性。由彎曲測試可知，未經退火之傳統鉬金屬背電極在承受0.16%伸張應力與0.28%壓縮應力測試後，並無出現明顯的電阻增量，而未經退火之鋁鉬與銀鉬合金電極其特性並沒有優於傳統鉬金屬結構；為了活化合金與改善薄膜品質，鉬金屬、鋁鉬與銀鉬合金被施予熱退火前處理，並做彎曲測試；結果顯示：退火製程可將此三種結構對伸張應力的承受度增加至0.42%，對純鉬金屬的效果又優於其餘兩種合金結構。

　　最後，銀奈米線鑲嵌之背電極結構包含：未經過與經過熱退火前處理的“鉬/銀奈米線/鉬”與“銀奈米線/鉬”結構。我們亦將它們做彎曲測試以評估其可繞性與可靠度改善之情況。為了使實驗結果更貼近實際情況，在彎曲測試前，銅銦鎵硒薄膜已藉由硒化製程被形成於銀奈米線鑲嵌之鉬金屬背電極上。實驗結果顯示：未經退火之實驗中，硒化製程所導致之薄膜裂紋將使兩種銀奈米線鑲嵌之背電極結構的起始電阻高於10 Ω，然而，在承受1.68%之伸張或壓縮應力之後，兩種奈米線鑲嵌結構皆可保持低於100 Ω之電阻；最後，經過熱退火前處理之“鉬/銀奈米線/鉬”結構可製作出無裂紋、低電阻（3.12 Ω, 1.04 Ω/□）之背電極，在經過五次0.84%伸張與壓縮應力測試後，仍保持低電阻之狀態。

　　從“鉬/銀奈米線/鉬”背電極之0.84%伸張與壓縮應力測試結果可知：銀奈米線鑲嵌之鉬金屬背電極是一個具有潛力之薄膜，可應用於可繞式太陽能電池之背電極以增加其可繞度與可靠度特性。

In this thesis, we investigated the strain-induced reliability of back-contact for electrode deposited on polyimide (PI) substrate for flexible CIGS solar cells applications, and we integrated the electrode with silver nanowires (NWs) to enhance the flexibility of the back-contact electrode. The thesis content can be divided into three subjects. The first one is the investigation of cracks induced by the internal strain resulting from the fabrication process and the method we used to fix cracks of the conventional Mo back-contact electrode. For the second subject, the reliability of pure Mo and Al- or Ag-added Mo structures were evaluated by a home-made bending tester. For the last subject, silver NWs-embedded contacting layers as an electrode were evaluated. It demonstrated superior performance with minimal resistivity evolution before and after the bending tests and more flexibility than the conventional Mo electrodes.

First, various efforts to reduce process-induced strain, such as lowering the annealing ramping rate, depositing an additional back-side Mo film, and adding an Mo annealing pretreatment, were investigated. The annealing ramping rate was adjusted from 25 to 5⁰C/min to minimize the thermal stress of Mo film but had no success in fixing the cracks. Neither could the additional back-side Mo film fix the cracks, but only served to reduce the sample curving after the selenization process. In one instance, crack of Mo electrode was fixed by a one hour 390⁰C annealing pretreatment, but the reproducibility was very low. The annealing pretreatment could improve the Mo film quality and partially alleviate the process-induced strain.

For the second subject, we fabricated Al- and Ag-added Mo structures, including MoAl, MoAg alloys and Al/Mo, Ag/Mo bi-layer structures, as alternative contacting layers. The annealing pretreatment was applied to these structures for further improvement. A bending test was designed to study the flexibility of these various structures. For the as-deposited films, none of the Al- and Ag-added Mo structures exhibited a better performance in the bending test than that of the conventional Mo, which could sustain 0.16% tensile strain and 0.28% compressive strain without obvious resistance increment. The annealing pretreatment did boost the sustainability of tensile strain up to 0.42% for Mo, MoAl and MoAg structures, but the pretreatment on pure Mo is more effective than those impurity-added Mo structures.

In the final subject, the silver NWs-embedded Mo layers, Mo/Ag NWs/Mo (MAM) and Ag NWs/Mo (AM) structures, with or without annealing were studied. CIGS film was formed on these structures for further investigation. For the as-deposited structures, macroscopic cracks occurred on the CIGS films and the electrode layers after the selenization process. Their resistances were increased to 100 ohm from tens ohm under 1.68% highly tensile or compressive strain. For the annealed structures, crack-free electrodes with low resistance (3.12 Ω, 1.04 Ω/□) were observed. They demonstrated more flexible (resistance kept below 5.6Ω and 3.2 Ω after 5-cycle 0.84% tensile and compressive bending respectively) and the superior performance of the MAM electrode is reproducible.

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