第三章 研究結果與討論
3.3 奈米線太陽能電池
3.3.3 不同蝕刻長度的影響
在討論不同蝕刻長度的實驗中，吾人利用5 mM 的硝酸銀與 5 M 的氫氟酸混 合溶液，在攝氏20 度下浸泡 1 分鐘以進行銀沈積。之後分別浸泡 0.1 M 過氧化氫 與5 M 氫氟酸的混合溶液 0 秒、30 秒、1 分鐘與 5 分鐘後製作成太陽能電池，並 進行電性與光學性質的量測。 圖 3-20 顯示反射率的確隨著蝕刻時間的加長而降低。
尤其是波長在300 至 400 奈米與 1000 至 1100 奈米的地方下降的幅度最大。
圖3-20 不同蝕刻時間對反射率的影響
0 10 20 30 40 50
300 500 700 900 1100
Re fl ec ta nc e (%)
Wavelength (nm)
0s
30s
1min
5min
52
由圖 3-21 可以觀察到當蝕刻時間上升，開路電壓隨著蝕刻時間的提高維持一
定的數值，顯示奈米線的長度與開路電壓的關係並不明顯。但電流密度方面隨著 蝕刻時間的上升與亦有先升後降的關係，與Huang 等人的結果類似[51]。由圖 3-22 的結果顯示蝕刻時間的加長會導致短波長的響應下降，但中與長波長的響應則是 先升後降。綜合兩者效應導致電流密度先升後降。顯示蝕刻長度在數百奈米左右 是較佳的條件。
圖3-22 不同蝕刻時間的電流密度-電壓曲線
0 5 10 15 20 25
0 0.2 0.4 0.6
Curre nt D ens it y（ mA/cm
2）
Voltage（V）
0s
30s 1min
5min
圖3-23 不同蝕刻時間對光譜響應的影響
54
圖3-25 多晶矽與單晶矽奈米線太陽能電池的光譜響應
56
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