臺灣博碩士論文加值系統

將太陽能電池的電極和射極設計於背面的概念，造就交指式太陽能電池在未來市場是很有潛力達到高轉換效率的。在本篇論文中，我們提出了一具有溝槽式本體和交指式背接觸電極異質單晶矽高轉換效率太陽能電池(A Trench-shaped Crystalline Silicon Heterojunction Solar Cell with an Interdigitated Back Contact Structure, TS-IBC )。傳統HIT太陽能電池上表面使用之金屬電極不透光，使得光子進入本體層時有一遮蔭效應，讓部分光源無法進入本體而被吸收。本論文使用交指式背電極架構，將表面電極全設計於背面，克服遮蔭效應且讓光完全進入本體吸收層。我們並將本體蝕刻出一溝槽形狀(Trench-Shaped)，此延伸的溝槽本體可以產生更多光產生載子，進而提升整體元件的短路電流密度。藉由溝槽本體，射極端能更有效收集少數載子，而背表面電場的分佈可以更廣泛有利於加速載子傳輸，減少少數載子的復合，使TS-IBC太陽能電池可以達到高轉換效率。在本論文中，幾種影響太陽能電池轉換效率之重要因素將被模擬和探討。諸如：表面是否形成一前表面電場層、溝槽深度、溝槽寬度比和薄膜厚度變化對元件特性之變化，和表面復合速率、面積和溫度對轉換效率的影響。結果在基本電性上，我們發現相對於無溝槽式的IBC太陽能電池，新TS-IBC太陽能電池會有6.03 %之短路電流密度提升，進而提升了轉換效率。此新架構的交指式背接觸電極太陽能電池的轉換效率可高達27.76 %，比現今轉換效率為25.6 %的IBC太陽能電池改善7.79 %的轉換效率。

The concept of locating the emitter and electrodes of a solar cell at the rear thereby creating an interdigitated back contact has great potential to achieve higher power conversion efficiency in the future market. In this paper, we propose a new heterojunction with intrinsic thin-layer (HIT) structure with interdigitated back contacts and rear trench-shape body, called as TS-IBC solar cells. The conventional HIT solar cell is limited by the optical losses on the front grid caused crystalline silicon substrate cannot absorb a part of sunlight. In this paper, having all contacts on the rear side to form interdigitated back contact, which can overcome the shadowing loss. Furthermore, the crystalline silicon substrate of the new cell is etched into trench shape. This extended trench shape can generate more photo-generated carriers to achieve higher short-circuit current density and the emitter can allow more minority carriers being collected. The back surface field can also extend through the extended trench shape body to accelerate carrier transmission resulting in carrier recombination was reduced. So, the TS-IBC solar cell of crystalline silicon heterojunction structure can achieve higher power conversion efficiency. Several key factors affecting the power conversion efficiency of the solar cell, such as front surface field, trench depth, trench width ratio, film thickness, surface recombination velocity, pitch and temperature are also simulated and investigated. The TS-IBC structure is optimized by using TCAD software. Then, we found that this new structure has a higher short-circuit current density which is about 6.03 % higher than that of the conventional IBC cell. Also, the new TS-IBC structure achieves power conversion efficiency 27.76 % which is about 7.79 % better than that (25.6 %) of the conventional IBC HIT solar cell.

中文論文審定書 i
英文論文審定書 ii
誌謝 iii
中文摘要 iv
英文摘要 v
圖次 viii
表次 xiii
第一章 導論 1
1.1 研究背景 1
1.2 論文回顧 2
1.3 動機 7
第二章 元件製作 9
2.1 模擬元件 9
2.2 元件實作 12
第三章 元件設計與模擬 15
3.1 一具有溝槽式交指背接觸異質單晶矽高效率太陽能電池 15
3.1.1 模擬之物理模型 15
3.2 IBC太陽能電池 16
3.3 溝槽式交指背接觸太陽能電池 18
3.3.1 元件結構說明 19
3.3.2 輸入特性曲線 20
3.4 交指式太陽能電池的邊際效應之比較 60
3.5 太陽能電池實作結果與量測 63
3.5.1 傳統無溝槽IBC太陽能電池之I-V量測。 65
3.5.2 TS-IBC太陽能電池之I-V量測 67
第四章 結論與未來展望 69
4.1 結論 69
4.2 未來展望 70
參考文獻 71
附錄A 77
矽晶太陽能電池結構 77
太陽能電池的基本參數 78
短路電流密度 (Isc) 79
開路電壓 (Voc) 79
填充因子 (F.F.) 80
轉換效率 (η) 81
太陽光譜 83
內部量子效率 84
外部量子效率 85
異質接面 (Heterojunction) 85
抗反射層 86
前表面電場與背表面電場效應 88
太陽能電池損失能量來源 88
輻射復合 (Radiative Recombination) 89
蕭克力萊德霍爾復合 (Shockley-Read-Hall Recombination) 90
歐傑復合 (Auger Recombination) 90

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