N型矽基板之同質與異質接面太陽能電池

N-type silicon based homojunction and heterojunction solar cells

黃昱閎(Yu-Hung Huang)

指導教授 ： 劉致為

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.10805

摘要

由於矽晶太陽能電池的穩定性以及高轉換效率，使矽晶太陽能電池在太陽能產業上佔了極大部分，雖然此技術在量產上的結構已經發展的很完整，但是在高轉換效率的技術上能存在許多的挑戰。
本論文中，N型矽基板上同質接面太陽能電池的製程是利用離子佈值技術來製作射極(硼)以及背面電場(磷)。利用合適的退火條件，離子佈值中摻雜離子可以被活化;且佈值中造成的損害可以被修復。本論文中研究包含快速熱退火以及爐管退火。快速熱退火製程轉換效率為14.5%而爐管熱退火製程效率為15.4%。此外，為了更佳的效率，電極的製作、材料，以及電極的厚度條件都予以考慮。因此，在本論文中設計了不同在沉積電極後的退火條件以及不同電極材料、厚度的實驗。
另外，由於表面鈍化對於開路電壓有極大的影響關係進而影響太陽能電池轉換效率，因此表面鈍化是十分重要的。利用準穩態光導量測比較不同沉積法的氧化鋁(Al2O3)層之鈍化能力，而較高的有效載子生命周期代表較佳的鈍化能力。此外，準穩態光導量測也提供預估形成介面後太陽能電池的暗示開路電壓之一種方法。利用原子層沉積氧化鋁出色的鈍化能力，本論文中最高轉換效率超過16%。
最後，N型矽基HIT結構太陽能電池達到的轉換效率為11.1%，以此討論非晶矽射極的優點以及適當的後退火條件。

關鍵字

n型矽基 ； 鈍化 ； 原子層沉積 ； 準穩態光導 ； 異質接面薄本質層

並列摘要

Wafer based solar cell accounts for the production of a large part in photovoltaic industry due to its stability and high efficiency. Although the technology of wafer based solar cell has been well-developed for conventional structure, there are still numerous new challenges existing for high efficiency solar cell.
In this thesis, the fabrication process of n-type silicon based homojunction solar cell is demonstrated by using ion implantation to form the boron (p+) emitter and phosphorous (n+) back surface field. By using appropriate annealing condition, The implanted dopants and damage introduced by implantation can be activated and repaired, respectively. Both rapid thermal annealing (RTA) and furnace annealing were investigated within this work. The efficiency is 14.5% by RTA process and 15.8% by furnace annealing process. Moreover, contact formation, contact material, and contact thickness conditions are taken into consideration for better efficiency. Therefore, experiments of various annealing conditions in forming gas after depositing contact, different material, and the thickness of contact are designed in this work.
Next, surface passivation is very important for solar cell efficiency due to its strong dependence on open circuit voltage so it affects solar cell efficiency. Aluminum oxide (Al2O3) layers deposited by different method are compared for passivation ability by using quasi-steady-state photoconductance and photoluminescence (QSSPC) measurement.
It means better passivation ability to passivate solar cell for higher effective carrier lifetime. In addition, QSSPC measurement also provide a way to estimating the implied open circuit voltage after forming the junction of solar cells. With the excellent passivation of Al2O3 deposited by atomic layer deposition (ALD), the efficiency more than 16% is shown in this work.
Finally, the n-type silicon HIT solar cell with 11.1% efficiency is demonstrated to discuss the benefits from amorphous silicon emitter and suitable PDA condition.

並列關鍵字

n-type silicon based ； passivation ； ALD ； QSSPC ； HIT

參考文獻

chapter 1

[2] H.J. Moller, C. Funke, M. Rinio and S. Scholz, Multicrystalline silicon for solar

cells” , Thin Solid Films 487 (2005), pp. 179–187.

[3] Rech, B. and Wagner, H., 1999. Potential of amorphous silicon for solar cells. Appl. Phys. A 69, pp. 155–167.

[4] Martin A. Green, Keith Emery, Yoshihiro Hishikawa and Wilhelm Warta, “Solar cell efficiency tables (version 37)”, Prog. Photovolt: Res. Appl. 2011; 19:84.