P3HT:PC₆₁BM Based Solar Cells Employing Solution Processed Lead Iodide As The Hole Transport Layer

More and more researchers are interested in polymer solar cells because of its light weight, wide material sources and easy fabrication process. When the active layer is sandwiched between two electrodes, the simplest polymer solar cells are successfully fabricated. There are several different kinds of interfaces appearing in the polymer solar cells, for example, inorganic/organic interface, organic/organic interface, and organic/metal interface and so on. If the interfaces can have good contact and proper energy level with each other, the electrons or holes can be transported efficiently thus leads to better power conversion efficiency.We try to develop novel anode buffer layer materials with good interfacial contact and energy level alignment. The main content of the thesis are as follows:?1? A novel hole extracting buffer layer material, namely PbI₂, was developed for polymer solar cells. The Pb I2 effect was investigated on the prototype ITO/P3HT:PC₆₁BM/Al solar cell devices. After optimization, the open circuit voltage is 0.5 V, short circuit current density is 8.16 mA·cm-2 and the fill factor is 0.52. Compared with the devices without any buffer layer?efficiency of 0.85 %?, the power conversion efficiency of 2.13 % was obtained by using PbI₂ as the buffer layer.?2? Composite materials of PEDOT: PSS with graphene oxide or PbI₂ were prepared to partially replace well-known anode buffer layer material PEDOT: PSS. Then these composite were employed in polymer solar cell.