Improvment Of The Inverted Polymer Solar Cells With The ZnO、CdS(Se) Nanomaterials Interlayer

The organic solar cells show a promising application prospect in the mass production oflow cost and flexible products. However, short exciton diffusion length and low electrontransfer rate are the characteristics of organic photo-sensitive materials. These factors limittheir application in organic photovoltaic preparation. Using the high mobility inorganicnanomaterials as electron transport layer can improve the electronic conduction ability and thepower conversion efficiency of the device. Among the inorganic nanomterials, the II-VIchalcogenides nanomaterials are considered to be the ideal materials to prepare organic solarcells. They have many advantages, such as, high carrier mobility, stable chemistry, low costand simple preparing process.We applied the nanomaterials to optimize the electrons transportation of the organic solarcells. It included the passivation of nanomaterial defect and the application for high crystalporous three-dimensional nanstructrue materials.Primarily, CdS and CdSe semiconductor nanomaterials were used as electron-transportlayer for their good controllability for the morphology of materials. In addition, they werematch well with P3HT:PCBM work function level. High crystal, slice and porous structurewere the advantages for these nanomaterials. These characteristics contributed to the highexctions separation efficiency and smooth electrons transportation. We tried to enhance thepower conversion efficiency of the inverted solar cells by optimized the materials thicknessand the active layer thickness.Then, we prepared the porous and single crystal ZnO nanoflowers with differenthydrothermal reaction time (6h,9h and12h). The morphology and photoelectricalproperties of porous ZnO nanoflowers were investigated. The results revealed that the porousZnO nanoflowers for9h reacting were a kind of ideal electron-selective layers materials.Finally, ZnO nanoflowers were employed in the organic solar cells as electron-selective layer.Compared with the control device without ZnO interlayer, the optimized device with ZnOinterlayer of growing for9h showed a higher short circuit current density of5.68mA/cm2and photoelectric conversion efficiency of1.24%.Finally, we investigated the effects of rapid UV-ozone treatment to ZnO nanofilms (ZnONFs) on the performance of the inverted organic solar cells. The device with20s UV-ozonetreatment was8.22%and12.42%enhancement in short circuit current and photoelectricconversion efficiency, respectively. We concluded that oxygen vacancy defects were oxidizedthrough UV-ozone treatment of ZnO NFs. It decreased the internal resistance and improvedthe charge transfer property at the ZnO NFs/polymer interface.