Study On Poly(3-hexylthiophene) Based Polymer Solar Cells

In this thesis, device performance of Poly(3-hexylthiophene) polymer solar cells is studied under its various morphologies and structures in order to optimize its structure and to improve its performances. The main tasks are following:The photoelectric converting performance of polymer solar cells is studied when metal oxide is used as buffer layer. Classic p-P3HT/n-TiOx bilayer solar cells are fabricated in this study. In our bilayer devices, TiOx and P3HT are used as acceptor and donor materials respectively. It is well known that a blend of P3HT and PCBM is very effective for the active layer. The performances of devices are significantly improved by replacing the buffer layer according to sol-gel method and spin-coating fabricated films, or by optimizing the thicknesses of device layer.Preparation process of TiOx and NiOx precursors are researched. Three fundamental structures of the organic polymer solar cell are fabricated by the sol-gel method and spin-coating way. The photovoltaic efficiency of devices is tested respectively and the relative theory is analyzed. In addition, we get the preparation method of the bulk-heterojunction photovoltaic devices.Based on the semiconductor material Forouhi-bloomer (F-B) model and Matlab software, the thicknesses and optical constants of the films which are prepared in device structure are tested by using spectroscopic ellipsometry. In this thesis, photo current of the bulk-heteroj unction photovoltaic devices has been specifically discussed by adopting the classical electromagnetic theory, photoelectric converting theory and the theory of carrier transport theory. The J-V characteristic of the device is definitely and quantitatively studied based on the model of Onsager-Braun and the Drift-Diffusion equations.