本實驗主要在探討摻雜鑭鐵酸鉍(BiFeO3, BFO)薄膜在不同厚度變化下所表現出來的光伏效應，藉由各項儀器來觀察鐵酸鉍薄膜在不同情況下所表現出來的差異性，再藉由分析這些差異性來推測影響光伏效應的可能機制與原因。
本實驗的鐵酸鉍薄膜以及導電緩衝層都是利用射頻濺鍍 (RF-Sputtering)，在矽(silicon)(100)基板上鍍製。先在矽(100)基板鍍上鎳酸鑭(LaNiO3, LNO)導電緩衝層，接著鍍25、50、75、100、150 nm不同膜厚的鐵酸鉍薄膜。最後，上電極是使用鋁摻雜氧化鋅(AZO)的薄膜。
分析的儀器分別是利用場發射電子顯微鏡來觀察膜厚變化，原子力顯微鏡來觀察表面粗糙度，X 光繞射儀來分析薄膜的結晶行為；紫外光-可見光光譜儀量測薄膜的光學性質，鐵電量測儀量測電滯曲線，keithley2400來測量電阻值，固態雷射(405nm)系統量測漏電流及光伏效應。
實驗發現，鐵酸鉍薄膜XRD隨著膜厚的增加，繞射峰訊號有往高角度移動，表示鐵酸鉍薄膜存在著應力釋放的現象，鐵酸鉍薄膜被應力釋放，使偶極矩的距離減少，內建電場也跟著減少，導致電子電洞被分離的能量減少。隨著厚度增加，電子電洞對到上下電極的距離增加，使得電阻值增加，導致效率降低。光伏效率是由離子的偏移量所主導，隨著膜厚的增加，由於電阻劇烈上升，導致極化值變化量被電阻效應所覆蓋。
發現不同膜厚下，鐵酸鉍薄膜光伏效應的強弱與結晶性、表面粗糙度、穿透率與漏電流量測，並無觀察到有任何明顯直接的關聯。

The photovoltaic effect was discussed under different thickness of Lanthanum doped BiFeO3 thin film. Thin film were deposited by RF-sputtering.First,LaNiO3 (LNO) was deposited on Si(100) substrate, then BiFeO3 was grown on LNO. The top electrode used aluminum doped zinc oxide (AZO). BFO thickness have 25, 50, 75, 100 and 150 nm, respectively, and the thickness was calibrated by X-ray reflectivity and field emission scanning electron microscopy. Surface roughness was carried out by atomic force microscopy. Lanthanum doped BFO have strain relaxation with film thickness increase which was observed from the peak position shift of theta-two theta scan of X-ray diffraction. As the film thickness increase, the dipole moment decrease and the built-in electric field decrease. The probability of electron-hole recombination become higher as the built-in electric field become smaller; therefore, the efficiency of photovoltaic effect become smaller. The polarization effect played an important role for efficiency of photovoltaic. As the film thickness increase, the resistance has a dramatic increase that dominate the efficiency of photovoltaic more than the polarization effect dominate. The efficiency of photovoltaic do not have straight correlation with film crystallinity, surface roughness, transmittance and leakage current by various measurements under different film thickness.

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