New Electron Transporting Materials Applied In Perovskite And Quantum Dots Solar Cell

The energy crisis has been acknowledged one of the toughest problems to our humankind in the near future.Solar energy is recognized as a clean and sustainable energy source and solar cell is a kind of photovoltaic device that can directly convert sunlight into electricity.Traditional silicon-based solar cells have many drawbacks such as high cost,no flexibility etc.,more and more research has focused on new generation solar cells.Perovskite solar cell has gained tremendous attention from all over the world boil down to their excellent optoelectronic properties and diversified manufacturing processes.Quantum dots solar cell,which own the special material size and physical properties,has made substantially progress in recent years.This thesis introduced two kinds of new electron transport materials:C60-N and SnO2 in perovskite solar cell and colloidal PbS quantum dots solar cell.In the first contribution,we disclosed the fabrication and characterization of efficient planar-heterojunction perovskite solar cells using novel amino-based fulleropyrrolidine(C60-N)as the electron transporting material(ETM).Compared to the widely spread PCBM,we found that C60-N not only can efficiently reduce the work function of the metal cathode but also can passivate the trap states of the perovskite surface,further resulting in improved carrier transport,photovoltaic performance and stability.In addition,it is found that C60-N can also significantly enhance the film PL life time and decrease the surface roughness.Devices using C60-N as the ETM exhibit a high power conversion efficiency(PCE)of 16.6%,significantly higher than the 12.3%of PCBM based ones.In the second contribution,magnetron sputtering technology was utilized to fabricated low temperature processed SnO2 thin film to replace ZnO as ETM and efficiency as high as 8.4%was achieved in PbS quantum dots solar cell.Due to the Voc and FF parameters are not good enough,it is suspected that there are some issues in the SnO2 surface.We combine the advantages of ZnO material by spin coated on a thin ZnO film on the SnO2 surface and a PCE surpassing 9%was obtained after optimization.These findings provide insight into the selection and design of new ETMs with desirable properties.