Wavelength dependence of transient photovoltage polarity

作者：Shi Quanmin; Hou Yanbing^*; Li Yunbai; Feng Zhihui; Liu Xiaojun

来源：Physics Letters A, 2008, 372(36): 5853-5854.

DOI：10.1016/j.physleta.2008.07.024

Using pulsed laser with different wavelengths, transient photovoltage (TPV) is investigated for the sandwich device of indium tin oxide (ITO)/poly (2-methoxy-5-(2'-ethylhexyloxy)-1, 4-phenylenevinylene) (MEH-PPV) (500 nm)/Al. At laser wavelength of 500 nm, a 0.1 millisecond negative TPV signal appears followed by a positive one lasting 40-80 milliseconds. With increasing laser wavelength the negative, signal becomes weak and disappears when wavelengths), lambda >= 560 nm. This work demonstrates the process of exciton dissociation at the interface between ITO and MEH-PPV. A new method measuring the relative dissociation rate at the interface between polymer and electrode is introduced. It is estimated that the dissociation rate at Al interface is 4-8 times of that at the ITO interface.

• 出版日期2008-9-1
• 单位北京交通大学