臺灣博碩士論文加值系統

在本論文中，主要利用電腦輔助設計軟體針對非晶矽基太陽能電池進行模擬與設計。並藉此進行元件設計的最佳化與討論其相關物理機制。
首先以單接面非晶矽與微晶矽太陽能電池進行模擬，並將模擬所得之照光下電流-電壓特性與實驗量測到之數據作比較，以確認所使用模擬參數之準確性。之後，根據實際電池的結構分析，針對透明導電層上的紋理結構進行尺寸最佳化與相關討論。得出在高深寬比的結構中，內部電場變化將會更顯著地影響電池產生的短路電流。
多接面太陽能電池已被利用為提升轉換效率的有效方法。利用非晶矽/微晶矽雙層堆疊的架構，進行中間反射層的設計分析。進行兩種三接面非晶矽基電池的模擬，得其紋理結構之最佳化結果。並討論在不同光譜下，雙接面電池中因為子電池光電流不匹配所造成的整體電池之特性變化。
從非晶矽基太陽能電池在高溫環境下的特性量測可知多序矽材料具有相近於非晶矽之溫度係數。而非晶矽/微晶矽雙層堆疊電池於低照度下的特性，得到模擬與實驗相近的趨勢。透過對單層非晶矽與非晶矽/微晶矽雙層堆疊電池進行劣化與回復的實驗，可以發現雙層電池具有較低程度之劣化與較易於回復之特性。對此易於回復的特性，提出可能之解釋與探討內部物理機制。

In this thesis, we used TCAD program to simulate and design the amorphous silicon based solar cells. According to simulation results, the optimization of solar cell design and related physical mechanism can be obtained.
The simulated illumination current-voltage characteristics of single junction a-Si:H and μc-Si:H were compared to experimental results for verifying the accuracy of material parameters. Based on the analysis of realistic thin film Si solar cells, the optimizations of surface textures were done and some discussions were given. It turned out that the change of built-in electric field will affect the generated short-circuit current more significantly in a high aspect ratio texture structure.
The multi-junction solar cell design was considered as a way to increase the conversion efficiency. The analysis and design of an intermediate reflector layer inserted between a-Si:H and μc-Si:H were done. Two triple-junction a-Si:H based solar cells were simulated and their texture optimizations were given as well. The current mismatch effect of the micromorph tandem cell caused by spectrum variations was discussed.
According to the characterizations of a-Si:H based cells under high temperature conditions, polymorphous silicon was found to have a similar temperature coefficient like a-Si:H. The simulation results of the micromorph tandem cell under low irradiance conditions showed consistent trend with experimental results. Through experiments on degradation and recovery of single junction a-Si:H and the micromorph cells, it is found that the micromorph cell had minor light-induced degradation and enhanced recovery compared to single junction a-Si:H cell. The reason of this enhanced recovery and its physical mechanism were discussed.

ABSTRACT VII
TABLE OF CONTENTS IX
LIST OF FIGURES XII
LIST OF TABLES XVI
CHAPTER 1 INTRODUCTION 1
1.1. MOTIVATION 1
1.2. ORGANIZATION 2
CHAPTER 2 SINGLE JUNCTION AMORPHOUS SILICON BASED SOLAR CELLS 4
2.1. INTRODUCTION: TCAD SIMULATION OF THIN FILM SILICON SOLAR CELLS 4
2.2. MODELING OF SINGLE JUNCTION P-I-N SOLAR CELLS 5
2.2.1. Physics of p-i-n diode 5
2.2.2. Basic simulation structure 6
2.2.3. Amorphous silicon solar cells (a-Si:H) 7
2.2.4. Microcrystalline silicon solar cells (μc-Si:H) 10
2.3. LIGHT-TRAPPING IN THIN FILM SOLAR CELLS 13
2.3.1 Textured surfaces in thin film solar cells 13
2.3.2 Front textured surface 15
2.3.3. Back textured surface 18
2.3.4. Front and back textured surfaces 21
2.4. SUMMARY 27
REFERENCES 28
CHAPTER 3 MULTI-JUNCTION AMORPHOUS SILICON BASED SOLAR CELLS 30
3.1. INTRODUCTION: ADVANTAGES OF MULTI-JUNCTION SOLAR CELLS 30
3.2. MICROMORPH SOLAR CELLS 33
3.2.1. Amorphous/microcrystalline silicon tandem solar cells 33
3.2.2. Intermediate reflector layer in micromorph cells 34
3.3. AMORPHOUS SILICON BASED TRIPLE-JUNCTION SOLAR CELLS 39
3.3.1. The simulations of AGU and AUU triple-junction cells 40
3.3.2. Texture optimizations for AGU and AUU solar cells 43
3.4. CURRENT MISMATCH EFFECT 46
3.5. SUMMARY 53
REFERENCES 54
CHAPTER 4 CHARACTERIZATION OF AMORPHOUS SILICON BASED SOLAR CELLS 55
4.1. INTRODUCTION 55
4.2. HIGH TEMPERATURE EFFECT AND LOW IRRADIANCE EFFECT 56
4.2.1. High temperature effect 56
4.2.2. Low Irradiance Effect 62
4.3. LIGHT-INDUCED DEGRADATION AND RECOVERY OF AMORPHOUS SILICON BASED SOLAR CELLS 65
4.3.1. Degradation effect and recovery methods 65
4.3.2. Recovery of single junction a-Si:H and micromorph solar cells 68
4.4. SUMMARY 75
REFERENCES 76
CHAPTER 5 SUMMARY AND FUTURE WORK 77
5.1. CONCLUSIONS 77
5.2. FUTURE WORK 79

Chapter 2
[1]M. Hack and M. Shur, J. Appl. Phys., 54, 5858 (1983).
[2]M. Hack and M. Shur, J. Appl. Phys., 58, 997 (1985).
[3]E. A. Schiff, Solar Energy Materials & Solar Cells, 78, 567 (2003).
[4]U. Dutta and P. Chatterjee, J. Appl. Phys., 96, 2261 (2004).
[5]W-Y Lin, Amorphous and Microcrystalline Silicon Thin Film Solar Cell Simulation, Master Thesis, National Taiwan University, Taipei, Taiwan (2009).
[6]C-Y Huang, CIGS and Micromorph Solar Cell Simulation, Master Thesis, National Taiwan University, Taipei, Taiwan (2010).
[7]A. V. Shah, H. Schade, M. Vanecek, J. Meier, E. Vallat-Sauvain, N. Wyrsch, U. Kroll, C. Droz and J. Bailat, Prog. Photovolt: Res. Appl., 12, 113 (2004).
[8]B. Yan et al., Appl. Phys. Lett., 83, 782 (2003).
[9]B. Yan et al., Appl. Phys. Lett., 85, 1955 (2004).
[10]A. Luque, S. Hegedus, “Handbook of Photovoltaic Science and Engineering” (2003).
[11]Yoshihiro Hamakawa, “Thin-Film Solar Cells: Next Generation Photovoltaics and Its Applications” (2003).
[12]A. H. Pawlikiewicz and S. Guha, IEEE Transactions on Electron Devices, 37, 403 (1990).
[13]K. Ding et al., Solar Energy Materials & Solar Cells, 95, 3318 (2011).
[14]K. Yamamoto et al., Appl. Phys. A, 69, 179 (1999).
[15]J. Muller et al, Solar Energy, 77, 917 (2004).
[16]J. Springer et al., Solar Energy Materials & Solar Cells, 85, 1 (2005).
[17]M. Berginski et al., J. Appl. Phys., 101, 074903 (2007).

Chapter 3
[1]A. S. Brown and M. A. Green, Physica E, 14, 96 (2002).
[2]F. Meillaud et al., Solar Energy Materials & Solar Cells, 90, 2952 (2006).
[3]J. Yang et al., Thin Solid Films, 487,162 (2005).
[4]B. Yan et al., IEEE 4th Photovoltaic Energy Conversion (2006).
[5]R.E.I. Schropp et al., Thin Solid Films, 516, 6818 (2008).
[6]D. L. Staebler and C. R. Wronski, Appl. Phys. Lett., 31, 292 (1977).
[7]M. Hack and M. Shur, J. Appl. Phys., 58, 1656 (1985).
[8]A. Klaver and R.A.C.M.M. van Swaaij, Solar Energy Materials & Solar Cells, 92, 50 (2008).
[9]J. Krc et al., Journal of Non-Crystalline Solids, 352, 1892 (2006).
[10]C. Das et al., Appl. Phys. Lett., 92, 053509 (2008).
[11]T. Söderström et al., Appl. Phys. Lett., 94, 063501 (2009).
[12]Z. Xu et al., J. Appl. Phys., 75, 588 (1994).
[13]J. Yang et al., Appl. Phys. Lett., 70, 2975 (1997).
[14]X. Deng et al., Solar Energy Materials & Solar Cells, 62, 89 (2000).
[15]J. Zimmer et al., J. Appl. Phys., 84, 611 (1998).
[16]J. Burdick and T. Glatfelter, Solar Cells, 18, 301 (1986).
[17]R. Adelhelm and G. La Roche, IEEE 28th PVSC (2000).

Chapter 4
[1]IEC standards 61215/61646.
[2]D. L. Staebler and C. R. Wronski, Appl. Phys. Lett., 31, 292 (1977).
[3]D. E. Carlson and K. Rajan, Appl. Phys. Lett., 69, 1447 (1996).
[4]D. E. Carlson and K. Rajan, J. Appl. Phys., 83, 1726 (1998).
[5]J.P. Kleider and P. Roca i Cabarrocas, Journal of Non-Crystalline Solids, 299–302 (2002) 599–604.
[6]Y. Poissant et al., Journal of Non-Crystalline Solids, 299–302 (2002) 1173–1178.
[7]K. Morigaki et al., Materials Science and Engineering B, 121, 34 (2005).
[8]A. Fontcuberta i Morral and P. Roca i Cabarrocas, Thin Solid Films, 383, 161 (2001).
[9]P. Roca i Cabarrocas et al., Thin Solid Films, 403 – 404 (2002) 39–46.
[10]P. Roca i Cabarrocas et al., Pure Appl. Chem., 74, 359 (2002).
[11]I. A. Yunaz et al., Jpn. J. Appl. Phys., 46, 1398 (2007).
[12]K. Emery et al., 25th PVSC (1996).
[13]D. L. King et al., 28th PVSC (2000).
[14]A. Klaver et al., Solar Energy Materials & Solar Cells, 92, 50 (2008).
[15]J. A. Schmidt et al., Physical Review B, 59, 4568 (1999).
[16]H.-C. Sun et al. J. Appl. Phys., under revision (2012).