在本篇論文中，我們在單晶矽 (c-Si) 基板上沉積高品質氫化非晶矽層 (a-Si:H) 減少懸浮鍵(dangling bonds)與載子複合和利用凹入式結構增加等效背電場 (Back Surface Field, BSF) 區域使短路電流 (Jsc) 增加。同時我們設計凹入與偏移背電場之雙面照光異質單晶矽太陽能電池兩種架構作為雙面照光應用。我們使用Silvaco TCAD Altas來進行太陽能特性模擬。在環境光強度 (intensity of albedo) 為30 %時，我們的凹入式背電場單晶矽太陽能電池 (Recessed Back Surface Field Silicon HeteroJunction solar cell, RBSF-SHJ) 短路電流與轉換效率 (η) 可達到 47.02 mA/cm2 與 30.16 %。與沒有凹入式結構的太陽能電池 (flat SHJ solar cell) 相比，短路電流與轉換效率可以增加9.14 %與9.2 %。當環境光強度為100 % 時，短路電流與轉換效率可以增加12.67 % 與 12.83 %。如果將上下對稱的背電場區域作相對位置偏移 (shift) ，在單面照光的情況下，與凹入式背電場單晶矽太陽能電池相比，填充因子 (FF) 可以從82.67 % 增加到 83.24 %。而在環境光強度為30 % 與 100 % 時,填充因子可以從82.9 %增加到 83.5 % 與 83.96 % 增加到 84.96 %。

In this thesis, we proposed recessed and shifted back-surface-field crystalline silicon solar cells with heterojunction for bifacial application. To achieve high efficiency in bifacial application, recessed Back-Surface-Field (BSF) are designed on the crystalline silicon (c-Si) wafer with high quality hydrogenated amorphous silicon layer to improve the short-circuit current (Jsc) and reduce the carrier recombination. We perform simulation analysis by utilizing Silvaco TCAD Altas. At an albedo intensity of 30%, our Recessed BSF (RBSF) Silicon HeteroJunction (SHJ) solar cell reaches a 47.02 mA/cm2 Jsc and 30.16 % of conversion efficiency (η) which is 9.14 % and 9.2 % more than the Jsc and η of flat SJT solar cell thank to the additional recessed BSF area. When the albedo intensity reaches 100%, the increase percentages of Jsc and η arrive 12.67 % and 12.83%, respectively. If we shift the relative position with respect to the symmetrical BSF structure, Fill Fact (FF) increases from 82.67 % to 83.24 % in the monofacial condition. At an albedo intensity of 30 % and 100 %, FF increase from 82.9 % and 83.5 % to 83.96 % and 84.96 %, respectively.

中文審定書 i
英文審定書 ii
致謝 iii
摘要 iv
Abstract v
Contents vi
Figure Captions viii
Table Captions xi
Chapter 1 Introduction 1
1.1 Background and importance 2
1.2 Motivation 9
Chapter 2 Device fabrication 12
2.1 Device simulation 12
2.1.1 Device fabrication 12
2.1.2 Physical models and parameters of simulation 13
2.2 Process flow of device 15
2.2.1 Recessed and shifted back-surface-field solar cell 15
2.2.2 Process flow and fabrication 15
Chapter 3 Design and simulation for new devices 17
3.1 Calibration for parameters of simulation 18
3.2 Recessed back-surface-field solar cell 20
3.2.1 Design of back surface field and high percentage of emitter region 20
3.3 Design window for depth of aluminum electrodes in the substrate (dAL) and width of emitter region (We) 22
3.4 Influence of the width (WAL) of aluminum electrodes on RBSF solar cell 27
3.5 Variation of doping concentration for each layer of RBSF solar cell 29
3.5.1 Optimizing doping concentration in the p+ layer of emitter region for RBSF solar cell 29
3.5.2 Optimizing the doping concentration (Nd_n+ layer) in the n+ layer of BSF region for RBSF solar cell 31
3.5.3 Optimizing substrate doping concentration of RBSF solar cell 35
3.6 Variation of the relative distance between top and bottom of BSF for RBSF solar cell 37
3.7 Performance in different albedos for RBSF solar cell and RSBSF solar cell 40
3.8 Influence of the n-type substrate quality (lifetime) of RBSF and RSBSF solar cell 44
3.9 Influence of temperature on RBSF and RSBSF solar cell 48
3.10 Influence of different ambient lighting on RBSF and RSBSF solar cell 52
Chapter 4 Conclusion and Future Work 56
4.1 Conclusion 56
4.2 Future Work 57
Reference 58
Appendix 70
A. Initial experimental results and discusses 70
A. 1 Monofacial condition 70
A. 2 Bifacial condition 71

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