N型離子佈植矽基太陽能電池研究

Abstract

在本篇論文中，著重在矽基板太陽能電池表面鈍化層的探討以及研究 n 型矽 基板太陽能電池的光電特性以及設計、製作、量測。為了使矽基太陽能電池達到 市電平衡，太陽能產業界面臨提高轉換效率和降低單位發電成本的挑戰。因此本 篇論文研究方向重視與產業界相容及其應用的廣泛性。 在論文的第二章中，主要探討傳統矽基板太陽能電池的二氧化矽鈍化層。由 於產業界在大量生產太陽能電池時，需要有效地確保鈍化層的品質、均勻度，因 此可藉由電性量測得知鈍化層在不同位置的電容等效厚度、介面缺陷和固定電荷。 第三章中，利用準穩態光電導和光激發光量測分析不同厚度氧化鋁在n 型矽基板 的鈍化效果來因應未來太陽能電池需要有效降低成本和提高效率的趨勢。然而為 了更進一步增進氧化鋁的鈍化效果，在氧化鋁與矽基板接面處利用多種化學溶液 成長介面氧化層分析。而第四章則選擇較長生命週期的n 型矽晶圓作為基板，利 用離子佈值製作出p+n 接面，接著成長介面氧化層和用原子層沉積成長氧化鋁以減 少表面的缺陷復合效應，提高開路電壓。最後將兩層表面做粗糙化結構，增加太 陽能電池的光捕捉能力，以提高短路電流。

In this thesis, the passivation layer of silicon based solar cell is investigated and the research of the enhancement of n-type silicon based solar cell is also studied. In order to reach grid parity, the solar cell industry must overcome the difficulties such as the improvement of high efficiency and cost down. Thus, the technology of passivation which could increase open voltage (Voc) is more significant. Much attention has been focused on technologies what are compatible with the solar cell industry and possible that they could be widely used. In this work, a capacitance-voltage (C-V) characterization is carried out on SiO2 films deposited by thermal oxidation at different positions in the furnace. Pad sizes of Aluminum in the Metal-Oxide-Semicondutor structure are different that it could make sure the uniformity of the films by the C-V measurement. The optimized thickness of Al2O3 is 24 nm obtained by quasi-steady-state photoconductance (QSSPC) method and photoluminescence (PL) measurement. To further improve surface passivation of Al2O3, the Al2O3 layers are deposited onto wet chemically grown silicon oxide. This work shows that SC1-based chemical oxide as the interfacial layer is the most suitable for Al2O3 passivation. Then, we apply the interfacial layer to fabricate n-type ion implanted solar cells. Next, we texturize both sides of surface for the capability of light trapping in our solar cell. The efficiency of 17% is demonstrated in the work.