臺灣博碩士論文加值系統

本研究探討氧氛圍對具氧化鎳電子阻擋層之單晶矽太陽能電池光電特性研究，由於氧化鎳其功函數及價帶與正型矽匹配且具有高能隙，因此能有效阻擋電子跟電洞復合當作電子阻擋層，首先，利用蒸鍍金屬鎳顆粒在蒸鍍時通入不同流量的氧氛圍下形成氧化鎳，觀察其在不同的鎳金屬厚度下的影響，接著再利用氧快速熱退火改變不同溫度及時間等條件下進行氧化鎳的改質製程，接著探討利用氧化鎳顆粒於不同厚度及氧氛圍下蒸鍍所形成的氧化鎳電子阻擋層特性，利用UV/VIS/IR光譜儀、紫外光光電子光譜儀及穿透式電子顯微鏡分析氧化鎳的各種材料特性。
實驗結果顯示，在氧氣流量為 10 sccm時，蒸鍍鎳金屬顆粒，厚度在 0.2 nm的光電轉換效率為17.5 %，由於在氧氛圍下蒸鍍鎳金屬時，較不易形成氧化鎳，所以嘗試利用氧快速熱退火改質，首先，在氧氛圍中蒸鍍鎳金屬後，於退火爐中用 300 ˚C 進行氧快速熱退火 2 min 並通入氧氣流量為15 sccm，其光電轉換效率為 14.8%，這是因為串聯電阻經過加熱之後從 1.95 Ω-cm2提升至 2.87 Ω-cm2，其原理為氧氣無法有效均勻擴散至鎳金屬形成均勻的氧化鎳，而在表面形成高阻抗，由於鎳金屬不易透過蒸鍍通氧及加熱形成氧化鎳，因此接續實驗改為氧化鎳顆粒進行蒸鍍，當源材料為氧化鎳顆粒時，氧氣流量為 0 sccm，厚度為 0.2 nm的光電轉換效率為 17.5%，將氧氣流量提升至30 sccm時，光電轉換效率提升至17.9 %，效率增加0.4 %，綜合以上結果，當蒸鍍氧化鎳顆粒時，在通入氧氣流量 30 sccm下，厚度為 0.2 nm時光電轉換效率為 17.9 %，開路電壓為624 mV、短路電流為35.1 mV/cm2、填充因子為 81.6 %及串聯電阻 1.7 Ω-cm2。

The effects of oxygen ambient in nickel oxide electron-blocking layers (EBLS) on photovoltaic characteristics of monocrystalline silicon solar cells (MSSCs) were investigated in this thesis. Nickel oxide which has wide bandgap, work function and valence band close to p-type silicon, has received as EBLs. First, nickel oxide was formed by evaporated nickel granules in different oxygen ambient. The effects of thicknesses of nickel were investigated. Furthermore, the characteristics of nickel oxide were adjusted by rapid thermal annealing (RTA) in various oxygen ambient and temperatures. Finally, the nickel oxides EBLs were formed by nickel oxide granules in oxygen ambient. The material properties were analyzed by the UV/VIS-IR spectroscopy, UV photoelectron spectroscopy (UPS), and transmission electron microscopy (TEM), respectively.
The experiment results indicate that the MSSCs with conversion efficiency (CE) of 17.5% were demonstrated at an oxygen flow of 10 sccm and evaporated nickel thickness of 0.2 nm. Since the nickel oxide was not easy formed by nickel in oxygen ambient, the RTA was used to modify the properties of nickel oxide. The MSSCs with CE of 14.8% was achieved at 300 oC for 2 min in oxygen flow of 15 sccm. The degradation mechanisms can be attributed to larger series resistance formed at the surface of nickel oxide. Thus, the nickel oxide was formed by nickel oxide granules in oxygen ambient. The MSSCs with CE of 17.5% was presented at 0.2 nm of nickel oxide under 5 x 10-6 torr. The achievement of CE improvement of more than 0.4% absolute from 17.5% to 17.9% for MSSCs with an oxygen flow of 30 sccm, was demonstrated. According to the optimum conditions, the MSSCs with the CE of 17.9%, open-circuit voltage of 624 mV, short-circuit current of 35.1 mV/cm2, fill factor of 81.6%, and series resistance of 1.7 Ω-cm2, were demonstrated by evaporated nickel oxide under the oxygen flow of 30 sccm and thickness of 0.2 nm.

摘要..........i
Abstract..........ii
誌謝..........iii
目錄..........iv
表目錄..........vii
圖目錄..........viii
第一章 緒論..........1
1.1電子與電洞選擇性材料應用於太陽能電池之文獻回顧..........1
1.2氧化鎳薄膜應用於光電元件之文獻回顧..........3
1.3針對利用不同方式形成氧化鎳之文獻回顧..........4
1.4研究動機..........5
1.5論文架構..........6
第二章 實驗流程與特性量測..........7
2.1在固定氧氛圍中，改變蒸鍍鎳金屬厚度所形成的氧化鎳之影響..........7
2.1.1去除矽基板表面附著物及原生氧化層( RCA cleaning )..........7
2.1.2利用氫氧化鉀( KOH )、異丙醇及去離子水混合溶液對晶片進行糙化處理( Texturing )..........8
2.1.3利用爐管對正面射極高溫磷擴散( Phosphorus diffusion )..........8
2.1.4利用氫氟酸混和溶液清洗擴散後磷玻璃( PSG removed )..........8
2.1.5利用濕式化學蝕刻在擴散後進行邊緣隔絕( Wet chemical edge isolation )..........8
2.1.6利用電漿輔助化學氣相沉積( PECVD )抗反射層氮化矽於正面( ARC deposition ..........8
2.1.7雷射切割試片( Laser cutting )..........8
2.1.8網印正面圖案化之銀電極( Screen-print Ag )..........9
2.1.9利用燒結爐燒結正面之銀膠( Firing )..........9
2.1.10正面旋塗抗蝕刻阻擋層( Spin coated polymer )..........9
2.1.11浸泡氫氟酸溶液蝕刻背面自然氧化層( Removed native oxide by..........9
2.1.12在腔體內通入氧氣後背面蒸鍍鎳顆粒形成氧化鎳電子阻擋層( Evaporation Ni in oxygen ambient )..........9
2.1.13背面蒸鍍銀電極( Evaporation Ag )..........10
2.2蒸鍍鎳金屬在不同氧氛圍下所形成的氧化鎳之光電特性影響..........10
2.3固定氧氛圍中蒸鍍鎳金屬後再利用氧快速熱退火形成氧化鎳之影響..........10
2.3.1對氧化鎳薄膜在氧環境下進行快速熱退火( Rapid thermal annealing in oxygen ambient)..........11
2.4真空中改變蒸鍍氧化鎳厚度形成的氧化鎳之光電特性影響..........11
2.4.1 在腔體內通入氧氣後背面蒸鍍氧化鎳顆粒形成氧化鎳電子阻擋層( Evaporation Ni in oxygen ambient )..........11
2.5不同氧氛圍下對蒸鍍氧化鎳所形成的氧化鎳之光電特性影響..........11
2.6太陽能電池特性量測..........12
2.6.1太陽能電池電流-電壓特性量測( I-V measure )..........12
2.6.2太陽能電池外部量子效率量測( EQE measure)..........12
2.6.3穿透式電子顯微鏡量測( TEM )..........12
第三章 氧氛圍對具氧化鎳電子阻擋層之單晶矽太陽能電池光電特性研究..........23
3.1探討在固定氧氛圍中，改變蒸鍍鎳金屬厚度所形成的氧化鎳之特性影響..........23
3.1.1改變蒸鍍鎳金屬顆粒所形成的氧化鎳厚度對太陽能電池之電流–電壓量測之分析..........23
3.1.2結論..........24
3.2探討蒸鍍鎳金屬在不同氧氛圍下所形成的氧化鎳之光電特性影響..........25
3.2.1改變蒸鍍鎳金屬顆粒在不同氧氛圍下所形成的氧化鎳對太陽能電池之電流–電壓量測之分析..........25
3.2.2結論..........26
3.3探討固定氧氛圍中蒸鍍鎳金屬後再利用氧快速熱退火形成氧化鎳之影響..........26
3.3.1改變固定氧氛圍中蒸鍍鎳金屬後氧快速熱退火溫度及時間對太陽能電池之電流-電壓之分析 ..........27
3.3.2結論..........28
3.4探討真空中改變蒸鍍氧化鎳厚度形成的氧化鎳之光電特性影響..........28
3.4.在真空環境下改變蒸鍍氧化鎳顆粒所形成的氧化鎳對太陽能電池電流–電壓量測分析..........28
3.4.2結論..........30
3.5探討不同氧氛圍下對蒸鍍氧化鎳所形成的氧化鎳之光電特性影響..........30
3.5.1蒸鍍氧化鎳顆粒時，在不同氧氛圍下形成的氧化鎳對太陽能電池電流–電壓分析..........30
3.5.2結論..........31
第四章 總結論與未來展望..........50
4.1總結論..........50
4.1未來展望..........50
參考文獻..........51
Extended Abstract..........54

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