本研究使用噴霧裂解法成功地製備可調控的鈦/鋁混合薄膜。藉由製程溫度和前驅物溶液的比例可以調控鈦/鋁混合薄膜的折射率、成份和電性等性質。在製程溫度低於380 ℃時，鈦/鋁混合薄膜的折射率大約維持在2.2，此時的折射率與純二氧化鈦的折射率相當接近。從EDX成份分析中也發現，此時薄膜的成份大多為鈦，且和前驅物的比例並沒有太大的關係。然而，當製程溫度高於380 ℃後，鈦/鋁混合薄膜的折射率開始產生改變，鈦/鋁混合薄膜內的鋁含量隨著前驅物內鋁的含量而增加，且此時混合薄膜的折射率產生變化，鈦/鋁混合薄膜的折射率隨著薄膜內鈦含量減少成線性的下降，此外，薄膜內的鈦和鋁的比例和前驅物內的鈦/鋁比例相當接近。少數載子生命週期的測量發現，隨著製程溫度增加使的薄膜內鋁含量增加讓鈦/鋁混合薄膜的載子生命週期增加。

我們利用的氧化鋁堆疊鈦/鋁混合薄膜之背部堆疊結構，做為鈦鋁混合薄膜應用驗證。由實驗結果發現，相較於鋁膠燒結後的反射率，此氧化鋁堆疊鈦/鋁混合薄膜結構使反射率有大幅的提升，反射率在長波長1200 nm下由25%提升至51%。預期反射率的上升能使短路電流增加，使太陽能電池效率提升。

Spray pyrolysis has been used to deposit (Al2O3)x(TiO2)1-x thin films with controllable properties successfully in this work. The deposition temperatures and the ratios between titanium precursors and aluminum precursors are main parameters controlling film properties, including the refractive index, components of the thin films and the electrical properties. When the deposition temperature is below 380 oC, the refractive index of (Al2O3)x(TiO2)1-x thin films are about 2.2 which is close to refractive index of titanium dioxide. From energy-dispersive X-ray spectroscopy (EDX), the components of (Al2O3)x(TiO2)1-x thin films with various ratio precursors have high content of titanium. As the deposition temperature increases higher than 380 oC, the refractive index of (Al2O3)x(TiO2)1-x thin films are decreasing with the Al precursors increasing. The EDX shows that the molar ratio of titanium and aluminum in thin films are closed to the ratio in the precursor’s solutions.
From the lifetime measurement, the higher deposition temperatures have higher lifetime and the lifetime of the (Al2O3)x(TiO2)1-x thin films increase with the contents of aluminum in the thin film increasing.
In order to know quality of (Al2O3)x(TiO2)1-x thin film, we implement this dielectric rear surface passivation stack：Al2O3 /(Al2O3)x(TiO2)1-x stack. Comparison from only Al paste for rear stack, our dielectric rear surface passivation stack can increase rear reflectance (at wavelength 1200 nm ) from 25% to 51%. This can be increase short-circuit current, and then increase efficiency.

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