. . . . . . . . . .    ANM 2010     3rd International Conference on Advanced Nano Materials     12-15 September 2010 - Agadir, Morocco Back    Abstract ANMM181 STATE OF THE ART IN ORGANIC PHOTOVOLTAICS AND CHALLENGES RELATED TO CARRIER TRANSPORT Vaidotas KAŽUKAUSKAS, Mindaugas PRANAITIS, Andrius ARLAUSKAS Semiconductor Physics Department and Institute of Applied Research of Vilnius University, Saulėtekio al. 9, bldg. 3, LT-10222 Vilnius, Lithuania . The present day achievements and activities related to organic solar cell development in Europe will be reviewed in our presentation. The analysis will be given focusing on the in-depth insight into microscopic transport and trapping phenomena. In photonic organic material engineering and device development carrier transport properties are of primary importance because namely these phenomena determine macroscopic material parameters conditioning device functionality and efficiency. In organic materials, which by their nature are highly disordered, charge carrier mobility is one of the main factors limiting carrier transport. On the other hand mobility (at least of one sign carriers in a given material) is often limited by severe carrier trapping. This results in an imbalance of different carrier flows, and requires specific technological measures to be undertaken to eliminate the problem. We are to demonstrate that carrier transport phenomena in materials that are mostly used for organic photovoltaics and devices on their basis are influenced in a complex way by the light-, electric field- and thermally- stimulated mobility and trapping effects, depending on the excitation conditions. Carrier mobility measurements were performed by the CELIV (Charge Extraction by Linearly Increasing Voltage) method, carrier traps were analyzed by the Thermally Stimulated Current spectroscopy, and Current-Voltage characterization was used to investigate carrier injection and contact properties. We will show that the complex experimental analysis by complementary methods enables discrimination and evaluation of numerical parameters of the mobility and trapping phenomena at different excitation conditions. Ageing effect is also a painful issue in organic device engineering. This phenomenon, which is related to material degradation caused by humidity, oxygen and/or elevated temperatures, will be addressed as well. We will demonstrate that, again, degradation is associated with the modification of microscopic charge transport properties. . © nanoAC . . . . . . . . . .

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