在高效矽晶太陽能電池中，有效抑制高摻雜的射極與集極的電子與電洞的復合速率是提升電池效率的一個重要關鍵。多晶矽接觸是少數幾種具有此種潛力的材料。它是將高摻雜多晶矽鍍製在經過氧化的矽晶基材所形成的結構體，一般稱為穿隧氧化層鈍化接觸(Tunneling Oxide Passivated Contact, TOPCon)，其可以有效抑制復合速率主要是利用夾在多晶矽與矽基材間的介面氧化層來抑制少數載子在氧化層表面進行復合，又可阻擋其進入多晶矽進行復合；因此能夠有效的降低飽和電流密度，提升整體太陽能電池效率。不過這層介面氧化層也會阻擋主要載子 (majority carriers) 的通過，進而升高接觸電阻 (specific contact resistance, c)，使得整體串連電阻上升降低電池效率，因此高性能的太陽能電池必須能同時滿足低Jo與低c的應用需求。
在本實驗中，為了研究如何同時得到低的飽和電流密度以及特徵接觸電阻，在分析飽和電流密度方面，我們使用硝酸和硫酸之濕式溶液成長方法來製備超薄界面氧化層，接著以低壓化學沉積法來製備多晶矽層，隨後透過高溫退火來將摻雜物活化，以達到高摻雜之目的。接著利用PCD量測法，分別獲得在不同退火溫度條件以及界面氧化層之飽和電流密度值。在分析接觸電阻方面，我們透過設計五道光罩來完成接觸電阻量測結構製備，最後在退火溫度875˚C，以硝酸成長之界面氧化層中獲得最佳參數為Jo=3.2(fA/cm2)，c=3.3(mΩ-cm2)。

To attain high-efficiency silicon solar cells, suppressing the recombination of electrons and holes at the highly doped emitter and collector is the key to increase the open circuit voltage and energy conversion efficiency. Polysilicon contacts are one of the few promising materials. It is a structure with heavily doped polysilicon and thin oxide layer on the silicon substrate, commonly called Tunnel Oxide Passivated Contact (TOPCon). The reason why TOPCon can effectively lower the saturation current density is that the interface oxide layer between the polysilicon and silicon substrate blocks the minority carrier to reach the polysilicon layer. However, this layer of interfacial oxide also blocks the major carrier to transport, thus increasing the specific contact resistance(c). Therefore, high-performance polysilicon must be able to meet both low Jo and c。
In our study, we aim to achieve the low saturation current density as well as the specific contact resistance. For the analysis of lowering the saturation current density, we fabricate chemical oxide layer by NAOS and SPM method. Heavily doped polysilicon layer is deposited through LPCVD, and the dopant is activated through high temperature annealing. Based on PCD measurement, We attain the saturation current density with different annealing temperature and interfacial oxide layer. For the analysis of specific contact resistance, we design 5 masks to fabricate the structure for measuring the specific contact resistance. Finally under the condition of NAOS growing interfacial oxide with annealing temperature 875˚C, we attain the best result of Jo=3.2(fA/cm2)，c=3.3(mΩ-cm2).

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