臺灣博碩士論文加值系統

本研究利用InGaAs量子點具有可調式能隙特性，成長不同能隙的量子點堆疊層，藉由實驗室分子束磊晶法（MBE）成長，我們稱這類結構為非對稱性量子點（AMQD），亦稱為寬波段量子點（Broadband quantum dot）。
首先，我們討論非對稱性量子點（AMQD）結構與非對稱性量子點綴於井（AM+DWell）結構的差異性，經由光激螢光、電激螢光及太陽電池特性分析後，AM+Dwell因有量子井的調變，將內部因成長量子點所累積的應力給改善，其Voc = 0.65 V，Jsc = 17.9 mA/cm2，FF=70.5 %，η=8.2 %。
接著，將AM+Dwell結構中的量子井調變不同濃度P型摻雜，濃度分別為Be= 2×1016 cm-3 、2×1017 cm-3 、2×1018 cm-3 ，經由光電特性、製作成太陽電池元件比較後，濃度為2×1017 cm-3，整體特性最佳，其Voc = 0.7 V，Jsc = 20.52 mA/cm2，FF=78 %，η=11.2 %。
AM+Dwell（2×1017 cm-3）轉換效率優化我們利用單層100nm SiO2、100nm ZnO、雙層50nm Si3N4/ 30nm ZnO及磨薄三種方法來提升元件轉換效率，經由不同優化方法提升轉換效率可得到最佳的結果為Voc = 0.73 V，Jsc = 27.4 mA/cm2，FF=75 %，η=15.0 %。
最後，將不同優化方法最佳結果進行聚光I-V量測，經由10到100個太陽量測後，由於太陽增加會增加光子數，進而光電流也隨之增加，在者開路電壓與光電流指數成正比，在80個太陽時，其Voc = 0.88 V，Jsc = 2000.7 mA/cm2，FF=81 %，η=17.83 %。比原先轉換效率11.2%增加59%。

III-V multi-junction solar cells (MJSC), which consist of different energy bandgap materials to match the solar spectrum, have been used in high concentrated photovoltaic (HCPV) to achieve high solar power conversion efficiency (η). Self-assembled InGaAs quantum dots (QDs) structure is expected to be a good candidate for solar cells capable of absorbing light near 1.0 eV. Furthermore, the energy bandgaps for the QDs can be tuned by changing the material compositions and the dot size. By stacking these QD layers of different energy bandgaps, the optical absorption in the infrared region can be enhanced.
First, we discuss difference of AMQD and AM+Dwell structure. After Photoluminescence (PL), Electroluminescence (EL) and Photovoltaic characteristics measurement, in asymmetric quantum dots-in-a-well solar cell, the strain effect of self-assembled quantum dots is relieved by form of quantum well. The asymmetric quantum dots-in-a-well solar cell has obtained an conversion efficiency Voc =0.65V, Jsc =17.9 mA/cm2, FF=70.5% and η=8.2%.
The conversion efficiency optimization of AM+Dwell（2×1017 cm-3）is using different solutions such as coating a layer of 100nm SiO2, 100nm ZnO, a double layers of (50nm)Si3N4/(30nm)ZnO, and thinning. The highest conversion efficiency performance of optimizing is Voc = 0.73 V，Jsc = 27.4 mA/cm2，FF=75 %，η=15.0 %。
For the Dwell structure, p-type doping concentration is changed by doping Be for 2×1016 cm-3, 2×1017 cm-3, 2×1018 cm-3 respectively. After comparison of photoelectrical properties and solar cell performance ,the dopant concentration of 2×1017 cm-3 has shown the optimal characteristics with a Voc = 0.73 V, Jsc = 27.4 mA/cm2, FF=75 % and η=15.0 %.
Finally, the optimized result of various methods is examined using concentration I-V measurement under simulated solar light of 10 to 100 suns. While increasing concentration suns, the photo-generate current enhances along with the number of photons increases, thus, the open-circuit voltage and the current coefficient is proportional to the light. At concentration of 80 suns, Voc = 0.88 V，Jsc = 2000.7 mA/cm2，FF=81 %，η=17.83 %, with conversion efficiency improvement of 59% compare to former.

論文審定書 i
摘要 iii
Abstract iv
總目錄 vi
圖目錄 vii
表目錄 ix
一、 緒論 1
1.1 介紹 1
1.2 研究動機 3
1.3 論文架構 5
二、 理論基礎與文獻回顧 6
2.1 太陽電池原理 6
2.1.1 太陽光譜[5] 6
2.1.2 太陽電池基本工作原理 8
2.1.3 太陽電池的電路模型[5] 9
2.1.4 太陽電池重要參數[9] 10
三、 研究方法與儀器架構 13
3.1 實驗樣品介紹 13
3.2 太陽電池製程步驟 16
3.3 量測Mesa元件製程步驟 21
3.4 光激螢光量測 25
3.5 電激螢光量測 26
四、 實驗結果與分析 28
4.1 不同量子點結構特性 28
4.1.1 光激螢光光譜分析 28
4.1.2 電激螢光光譜分析 28
4.1.3 I-V特性量測 33
4.2 P型調變量子點綴於井太陽電池分析 36
4.2.1 光激螢光光譜分析 36
4.2.2 電激螢光光譜分析 37
4.2.1 I-V特性量測 41
4.2.2 外部量子效率量測 45
4.3 太陽電池轉換效率優化 46
4.3.1 I-V特性量測 47
4.3.2 EQE量測 53
五、 結論 55
參考文獻 56

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