利用铁电薄膜研究体异质结型有机光伏器件的光电流极性

Investigation on Photocurrent Polarity of a Bulk Heterojunction Organic Photovoltaic Device Using a Ferroelectric Thin Film

制备了铌镁酸铅-钛酸铅(PMN-PT)铁电薄膜,并通过紫外-可见(UV-Vis)透射光谱、X射线衍射(XRD)和原子力显微镜(AFM)对其进行了表征.为了研究体异质结型有机共混膜的光电流特性,制作了氧化铟锡(ITO)/PMN-PT/有机共混膜/铝(Al)的光伏器件,调制激光照射下外加偏压的极性和大小变化将直接改变瞬态光电流的极性和大小,从而可在实验上证明传统体异质结型有机光伏器件的光电流极性是由器件阴、阳电极的功函数差所导致的内建电场的方向决定.同时也提出了一种利用铁电薄膜来研究体异质结型有机光伏器件光电流特性的新方法.

The ferroelectric thin film of lead magnesium niobate-lead titanate （PMN-PT） was fabricated and characterized using UV-Vis transmission spectroscopy,X-ray diffraction （XRD）,and atomic force microscopy （AFM）.To determine the photocurrent properties of the bulk heterojunction organic blend film a photovoltaic device with the structure of tin indium oxide （ITO）/PMN-PT/organic blend film/aluminum （Al） was fabricated.Under modulated laser irradiation the amplitude and polarity of the transient photocurrent varied with the bias voltage,which shows that the photocurrent polarity of a conventional bulk heterojunction organic photovoltaic device is determined by the internal electric field that is induced by the difference between the work function of the anode and cathode electrodes.A new method is proposed for investigating the photocurrent properties of bulk heterojunction organic photovoltaic devices.