近些年為了提升矽晶太陽能電池的效率，以PERC(Passivated Emitter and Rear Cell)架構的太陽能電池成為主流。製作PERC太陽能電池的製程中，背表面鈍化是必要的步驟。在本實驗中我們使用氧化鋁薄膜作為其鈍化層，氧化鋁薄膜使用濕式製程製作來降低成本。
本篇利用P型矽基板製作太陽能電池。首先，我們基板是經過磷擴散的p-n片，使用氯化鋁溶液塗佈在基板背面以形成氧化鋁薄膜作為鈍化層。為了探討背面鈍化效果我們量測經塗佈溶液後的裸片與商業藍片(後者的p-n片前表面上有沉積抗反射層)少數載子壽命。找出最佳的溶液濃度、退火溫度與退火時間。為了探討退火後之氧化鋁薄膜的材料特性，使用XPS、TEM來量測其成分與厚度。使用最佳的退火時間20分鐘且在退火溫度為450℃進行退火行成鈍化層。在退火後，我們在氧化鋁層上沉積一層氮化矽做為保護層，然後經過黃光製程形成氧化鋁/氮化矽堆疊層開口圖樣。後來，在正面鍍上一層氮化矽作為抗反射層，經過網印、燒結以得出的PERC太陽能電池，其最佳填充因子為75.7%、轉換效率為15.17%，比全面鋁的太陽能電池相比提升了0.64%。

In recent years, in order to improve the efficiency of crystalline silicon solar cells, the solar cells of PERC (Passivated Emitter and Rear Cell) structure have become mainstream. The passivation of the back surfaces of PERC solar cells is a necessary process. In this experiment, we used a Al2O3 film as a passivation layer, and manufactured this film by using a wet chemical process to reduce costs.
In this study, we used p-type silicon wafers to fabricate solar cells. First, the wafers were diffused phosphorus to form p-n junction and then was coated with aluminum chloride solutions on rear sides to make Al2O3 films as passivation layers. To investigate the passivation effect of wet chemically deposited aluminum oxide film on the back surface, we measured the lifetime of minority carriers for both bare wafers and blue wafers(the latter of which refer to the diffused wafer coated with an anti-reflective coating) after coated with aluminum chloride solutions. We have found the best solution concentration, annealing temperature and annealing time period. In order to investigate the material characteristics of Al2O3 after annealing, the elemental composition and the film thickness are measured by XPS and TEM, respectively. The best annealing time period for Al2O3 was 20 minutes at 450℃ to from a passivation layer. After annealing the Al2O3 film, we deposited a SiNx film as a protective layer on the Al2O3 layer, and then used the photolithography process to form the opening pattern of the Al2O3/SiNx stacked layer. Subsequently, a SiNx layer was deposited on the front surface of the cell, followed by screen printing of metal contacts and co-firing. The PERC structure of the solar cell has a fill factor of 75.7% and a conversion efficiency of 15.17%, the latter of which shows an increase of 0.64% compared with the Al-BSF solar cell.

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