本論文針對鍺晶低能隙的特性，開發以鍺晶為基板之鍺晶異質接合太陽能電池，研究重點在比較射頻電漿輔助化學氣相沉積氫化非晶矽以及氫化非晶鍺薄膜來鈍化矽晶或鍺晶表面之效果。實驗以反射式高能電子繞射儀觀察非晶薄膜成長於單晶晶片上之臨界結晶溫度，並以少數載子生命周期儀探討晶片之鈍化效果。
首先在氫化非晶矽薄膜成長於矽晶雙面上的實驗發現，在較快的薄膜成長速率及薄膜臨界結晶溫度曲線附近所沉積之薄膜可以得到較好的鈍化效果。具體條件為當長膜速率1.92 Å/s及基板溫度170℃下，製備氫化非晶矽於矽晶片時可獲得最佳晶片有效載子生命週期達1450 μs，此時另以200℃下對試片進行退火後，載子生命週期甚至可提升至1700μs。另一方面，沉積氫化非晶鍺薄膜於鍺晶的實驗探討發現，當長膜速率為2.3 Å/s及基板溫度為100 ℃下來製備氫化非晶鍺於鍺晶片時，可得到最佳之晶片有效載子生命週期為243 μs。以此條件來製作鍺晶異質接合太陽能電池時，得到電池開路電壓Voc為252 mV、短路電流Jsc為16.9 mA/cm2、填充因子FF為87%、太陽光電轉化效率為4.1%之太陽能電池。

This study focused on developing high-efficiency solar cells by utilizing Ge wafers that has a lower band gap of ~0.6 eV. Emphasis was placed upon investigating the passivation effect of hydrogenated amorphous layers grown on the surface of crystalline wafers.
First of all, we found that a better passivation of crystalline Si can be obtained by growing hydrogenated amorphous silicon (a-Si:H) thin layers at higher growth rates and also higher Si substrate surface temperatures. Experimentally it was found that quite a high Si wafer carrier lifetime of 1450 μs was obtained when a-Si:H was grown at a growth rate of 1.92 Å/s and a substrate temperature of 170. This wafer carrier lifetime was further enhanced to 1700 μs after 200℃ annealing. On the other hand, for the passivation of crystalline Ge by hydrogenated amorphous Ge (a-Ge:H), an optimized wafer lifetime of 243 s was obtained when the a-Ge:H thin layers were deposited at a growth rate of 2.3 Å/s and a substrate temperature of 100℃. The Ge heterojunction solar cell fabricated under this condition showed a high conversion ratio of 4.1%, with Voc = 252 mV, Jsc = 16.9 mA/cm2, and FF = 87%.

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