酞菁锂薄膜的光电流极性研究

Investigation on Photocurrent Polarity of Lithium Phthalocyanine Thin Film

利用旋转涂膜法和真空镀膜法制备了以酞菁锂薄膜为工作层的有机光电器件,结构为氧化铟锡/聚二氧乙基噻吩∶聚对苯乙烯磺酸/酞菁锂/聚偏氟乙稀/铝(ITO/PEDOT∶PSS/LiPc/PVDF/Al).在可见光和近红外脉冲激光照射下,研究了器件的光电流极性.在532 nm脉冲激光照射下,器件的外电路光电流方向从ITO流向铝;但在1064 nm脉冲激光照射下,其外电路光电流极性发生反向,即从铝流向ITO.酞菁锂薄膜的吸收光谱和X射线衍射谱图显示,其对可见和近红外光有非常广的吸收,且为x晶型.酞菁锂自由基的双极性特性可随入射光波长的变化而改变.

The organic optoelectronic device consisting of lithium phthalocyanine（LiPc） thin film as active layer with the structure of indium tin oxide/poly（3,4-ethylenedioxythiophene）∶ poly（styrenesulfonate）/lithium phthalocyanine/polyvinylidene fluoride/aluminum（ITO/PEDOT∶ PSS/LiPc/PVDF/Al） was fabricated by spin coating and vacuum deposition methods.The photocurrent polarities of the device under the irradiation of visible and infrared pulse laser were investigated,respectively.Under the irradiation of 532 nm pulse laser the photocurrent direction of the device in the external circuit is from ITO to Al,but the photocurrent polarity will reverse by the irradiation of 1064 nm pulse laser,namely,photocurrent direction is from Al to ITO in the external circuit.The absorption spectrum of LiPc thin film indicates its broad absorption in visible and infrared region and it belongs to x-form confirmed by X-ray diffraction.The ambipolar property of LiPc radical could vary with the wavelength of incident light,which induces the above phenomena.It will have potential applications in light controllable switch and infrared light detection.