Investigation Of Organic Film Donor-Accepter Heterojunction Solar Cells

Organic film solar cell consists of a single or a number of organic thin films which sandwiched between two electrodes. The organic film layers can absorb the radiation and convert it into electricity. In this thesis, the author focuses on principle, fabrication technique, and optimization design and performance measurement of organic photovoltaic devices (OPVD) with an instruction of donor-accepter (DA) heterojunction.The first part of this thesis describes the synthesis and purification of organic materials, emphasize purification by temperature gradient sublimation. Organic thin films are fabricated by the method of vacuum evaporation deposition and spin-coating. This part is devoted to the design of heating instrument and analysis of the relation between the thickness of film and the condition of evaporation deposition and spin-coating. The modality and UV-Vis absorbency are represented by AFM and UV-Vis spectrophotometer respectively.In the second, the 4 steps of organic photovoltaic principle are analyzed respectively, the structure of several types of OPVD was designed and fabricated, and the â… -â…¤ properties of them are analyzed.The third part is dedicated to the microcosmic theory of flat donor-acceptor (DA) heterojunction OPVD. The optical principle and diffusion theory are taking into account to calculate the profile of photo-electricity field and exciton concentration in the organic layers. The procedure of optical reflect, refraction and absorb followed by exciton diffusion are simulated in a model established with MATLAB. The relations of external quantum efficiency vs. the thickness of organic layers are available in virtue of the modeling. The optimized thicknesses of organic layers are introduced in the design of organic devices, which represents significant improvements in the â… -â…¤ property over the un-optimized one.The last part calculates and simulates the influence of limitation inside device on â… -â…¤ properties of a solar cell. In addition, design of an automatic measuring system for solar cells is recounted.