在本篇論文中，我們提出雙面均含鈍化射極與表面電場之對稱與交叉式太陽能電池且可應用於雙面照光，此兩種新型太陽能電池製程完全匹配於傳統局部背鈍化(Passivated Emitter and Rear Contact)太陽能電池製造流程。我們利用Silvaco TCAD Atlas模擬，並且利用已發表的文章進行參數校正。在理想的反照率條件下，對稱和交叉兩種架構能分別獲得88.78 % 和 106.74 % 能量增益 (energy boost)。然而交叉架構有較好的性能，經過分析後可以發現是因為有環繞電場,能分別獲得 40.18 mA/cm2 短路電流密度、0.67 V 開路電壓、81.07 % 填充因子 和 21.93 % 轉換效率。我們的交叉架構與PERC+ (Passivated Emitter and Rear Contact for bifacial) 相比，不僅改善了低bifaciality，且也分別提升了7.85 % 轉換效率和31.35 % 能量增益在雙面照光之下。在套用實際環境參數的反照率下，交叉架構都能維持優異的性能。在雪的環境下，交叉架構的能量增益可以達到102.06 % ，接近於理想的反照率條件。然而在白沙的反照率條件下，能量增益也能達到77.13 % ，其他反照率較低的環境下也能維持20 % 到30 % 之間。

This thesis proposes symmetrical and crossed double-sided passivation emitter and surface field solar cells for bifacial applications which are fully compatible with the Passivated Emitter and Rear Contact (PERC) fabrication process. Our simulations use Silvaco TCAD Atlas, calibrated by real measurements. At an ideal albedo level, these symmetrical and crossed structures boost energy by 88.78 % and 106.74 %, respectively. The reason for the crossed structure’s better performance is that it has a surrounding electric field. The crossed structure also obtains a 40.18 mA/cm2 short-circuit current (Jsc), a 0.67 V open-circuit voltage (Voc), an 81.07 % fill factor (F.F.) and a 21.93 % power conversion efficiency (ƞ). Compared with Passivated Emitter and Rear Contact for bifacial (PERC+), the crossed structure improves low bifaciality factor (ƞ) and increases ƞ by 7.85 % and energy boost by 31.35 % for bifacial. For more-realistic albedo levels, the structure also performs strongly. At the spectral albedo level of snow, the energy boost of the crossed structure is 102.06 %, which is close to the performance at ideal albedo. At the spectral albedo level of white sand, the energy boost is 77.13 %. At lower albedos, the energy boost remains between 20 % to 30 %.

中文審定書 i
英文審定書 ii
致謝 iii
摘要 iv
Abstract v
Contents vi
List of Figures viii
List of Tables x
Chapter 1 Introduction 1
1.1 Background 1
1.2 Motivation 5
Chapter 2 Device Fabrication 7
2.1 Device Simulation 7
2.2 Process Flow of Device 10
Chapter 3 Result and Discussion 12
3.1 Traditional Solar Cell Structure 13
3.2 Symmetrical and Crossed Double-sided Passivation Emitter and Surface Field Solar Cells 15
3.2.1 Distribution of Electron Carrier Density 18
3.2.2 Electric Field Direction 21
3.3 Optimization and Environmental Impact 23
3.3.1 Optimization of Emitter Ratio 23
3.3.2 Optimization of Substrate 27
3.3.2.1 Doping concentration of substrate 27
3.3.2.2 Thickness of substrate 29
3.3.3 Best optimization result 31
3.3.4 Effect of Temperature on Solar Cell 31
3.3.5 Effect of Environments 34
3.4 Comparison of Various Structures 37
3.4.1 Comparison of PERC+ and our structures 37
3.4.2 Performance Simulation for Various Structures 38
3.4.3 Effect of Different Spectral Albedos 40
3.4.4 Effect of Passivation Layer 42
Chapter 4 Conclusion and Future Work 45
4.1 Conclusion 45
4.2 Future Work 46
Reference 47
Apprendix 55

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