本實驗研究的目的在於二次退火對於PERC太陽能電池背面氧化鋁鈍化層，對於太陽能電池性能的影響。實驗中使用兩種不同晶片分別進行比較，其中一種是由中美矽晶公司沉積三氧化二鋁的晶片，另一種是由清大奈米中心所沉積三氧化二鋁的晶片。為了比較兩種晶片沉積三氧化二鋁前後的差異，由WCT-120找出各種晶片最佳的少數載子生命週期。
首先要找出三氧化二鋁與矽接面上最佳的場鈍化效果，必須找出氧化鋁層最佳的退火時間與退火溫度。中美矽晶公司使用的機台為原子層沉積，其所沉積出的氧化鋁進行退火，得到最佳退火時間為60秒，最佳退火溫度為700℃；而清大奈米中心使用的原子層沉積機台，所沉積出的氧化鋁進行退火，得到最佳退火時間為10分鐘，最佳退火溫度為525℃。
接著在晶片背面會鍍上氮化矽層，並進行二次退火步驟。而這兩種晶片的最佳二次退火時間皆為10分鐘，最佳退火溫度為400℃。最後在最佳參數的條件下所做出的PERC太陽能電池得到最高轉換效率為17.63%。而對於僅進行一次退火的PERC太陽能電池效率相比平均約有0.22%的提升。

The purpose of this study is to investigate the effect of second annealing on the performance of PERC silicon solar cells with rear-side aluminum oxide passivation layers .Two kinds of wafers were applied in the experiment. Al2O3 layers of the one kind were deposited by the Sino-American Silicon Products Inc ( SASPI ), and the other kind were deposited by the Center For Nanotechnology, Materials Science, and Microsystems, National Tsing Hua University(NTHU). In order to compare the difference between two kinds of wafers, the WCT-120 was used to find the best minority carrier lifetime for each kind.
First of all, to provide a good field-effect passivation at the Al2O3/Si interface, finding the best annealing time and annealing temperature is necessary.The best annealing time and annealing temperature for the wafers from SASPI were 60 seconds, and 700℃, respectively. For the wafers with oxide layers deposited by the atomic layer deposition(ALD) technique at NTHU, the best annealing time and annealing temperature were, respectively, 10 minutes and 525℃.
Subsequently, the back sides of these wafers were coated with silicon nitride layers and were processed with a second-time annealing. Both of their best times for the second-time annealing were 10 minutes, and the best annealing temperature was 400°C. At the best annealing condition, the PERC solar cells with ALD-deposited aluminum oxide layers have the best conversion efficiency of 17.63 %. With respect to the cells processed by only one annealing, this corresponds to an improvement of 0.22% on average.

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