Research On Materials With Super-Two-Dimensional Structure And Interface Of Organic Solar Cells

Organic solar cells(OSCs) have attracted much attention in the last decades, the power conversion efficiency(PCE) of the OSCs has been rapidly improved, and the highest PCE of the OSCs reported has exceeded 10%. But to realize low-cost production for OSCs, the PCE and stability of OSCs must be further improved. Generally, the PCE of OSCs is mainly affected by the active layers and the buffer layers. For further improve the PCE of the OSCs, and find new ways for future study, we optimize device fabrication and develop novel buffer layer. The main results are summarized as follows.A buffer layer of different kind of anionic conjugated polyelectrolytes was employed on the surface of ITO to enhance the efficiency of inverted organic solar cells. We have demonstrated that a series of anionic conjugated polyelectrolytes: PFEOSO3 K, PFEOSO3 Na, PFEOSO3NH? and PFEOSO3 Li, can be used as efficient cathode buffer layers for OSCs with inverted device structure. Compared with the device without cathode buffer layer, the devices with anionic conjugated polyelectrolyte as cathode buffer layer showed huge improvement of JSC, VOC, FF and PCE. The device spin-coated with PFEOSO3 K as buffer layer showed the best performance: PCE = 7.63%.A series of super-two-dimensional structure have been used in OSCs, in which the thickness of active layer and annealing temperature and morphology of the device have been optimized. The device used DHPT-SC as active layer showed the best performance: VOC = 0.91 V, JSC = 5.45 mA cm-2, FF = 0.34, PCE = 1.71%.