2014-01-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/682770Abstract: In the portion of charge exchange behavior, we will focus on the energy shift of HOMO of the donor with a designated cathode, calcium (Ca). Given that Ca has a relatively low work function compared with other common cathode metals, it tends to develop an ohmic-contact at the organic/cathode interface, which theoretically will improve the efficiency of solar cells. However, in practical device fabrications, the vapor deposition of energetic alkaline earth metals on polymer surfaces might induce chemical reactions, which will also affect the performance of devices. Therefore the mechanisms leading to the improvement of power conversion efficiency may be more chemically and electronically complicated. To confirm the inference we mentioned above, this proposed project will be devoted to the charge exchange between active layer and electrode. Via energy band analysis obtained from ultraviolet photoemission spectroscopy (UPS) and x-ray photoemission spectroscopy (XPS), the electronic properties and chemical interactions between P3HT:PCBM blended active layers and Ca cathodes can then be investigated.光電子能譜儀太陽能電池XPSphotoemission spectroscopy