本論文乃以未來世代高效率矽晶太陽能電池的技術發展為議題，針對鍺晶製作可能的鍺晶異質接合，分別探討鍺晶表面的清洗以及利用氫化非晶矽薄膜層作為鈍化層的效應。

我們發現以傳統矽晶RCA的清洗程序未能通用在鍺晶片上，因此重新建立清洗流程為下:首先將鍺晶片浸入丙酮跟酒精清洗表面有機物，後置入鹽酸和氫氟酸去除表面氧化物再以雙氧水浸泡數秒，最後仍需置入高真空腔體於450 ℃下退火得到洗淨的Ge(100) RHEED繞射點表面。

將清洗好的鍺晶沉積雙面16 nm厚的a-Si:H薄膜鈍化晶片後得到最佳晶片有效載子生命週期達291.3 μs。以此最佳化的條件製作本質層於n+ a-Si:H/i a-Si:H/c-Ge/i a-Si:H/p+ a-Si:H結構上，發現10nm的a-Si:H薄膜得到較適的有效載子生命週期112.7 μs。

In this paper, we studied several important issues concerning fabrication of crystalline germanium (Ge) hetero-junction using amorphous Si as the passivation layers. First of all, surface cleaning procedure of Ge wafers was established through a comparison with the conventional RCA cleaning procedure for Si wafers. An efficient way for surface cleaning of Ge included a series of organic solvents, HCl, and HF treatments with suitable concentrations. Then, a surface oxide layer was fabricated with intention through an immediate dipping in H2O2 solution after HF treatment. Finally a very clean Ge(100) was obtained, which was verified by RHEED, by removing the oxide layer using thermal annealing in a high vacuum chamber at temperatures ranging 450 ℃. After surface cleaning process, we use PECVD to grow 16 nm hydrogenated amorphous silicon (a-Si:H) for germanium surface passivation. The best minority carrier lifetime of the Ge wafer after a-Si:H double-side coated was 291.3 μs, which was further reduced to 112.7 μs after completion of n+ a-Si:H/i a-Si:H/c-Ge/i a-Si:H/p+ a-Si:H.

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