Efficient Solution Process Perovskite Solar Cell and Transparent electrode

In the first part of this thesis, the optimized performance of Perovskite solar cells in conventional structure using drop-casting solution process has been achieved. Devices performance were sequentially improved by several testing, including thickness and the layer number of titanium dioxide (TiO2) which is used as electron transporting layer (ETL), annealing time, annealing temperature and thickness of Perovskite which is used as light absorption layer, thickness of hole transport layer (HTL) of N2,N2,N2′,N2′,N7,N7,N7′,N7′-octakis(4-methoxyphenyl)-9,9′-spirobi [9H-fluorene] -2,2′,7,7′-tetramine (Spiro-MeOTAD) and anode(Au) .The mechanisms behind for each part have been discussed as well. Via the measurement of Scanning electron microscopy(SEM) and X-ray diffraction(XRD),it proves that the drop-casting process is beneficial for crystallization of Perovskite. Finally the power conversion efficiency of the Perovskite solar cells in this study has achieved over 15.7%, with a filling factor (F.F) of 72%. In the second part, we successfully fabricate inverted perovskite solar cells using graphene as bottom anode. In order to convert graphene’s hydrophobic nature into hydrophilic, we insert a buffer material called HBC-6ImBr (Hexa-peri- hexabenzocoronene-6ImBr) between graphene and HTL. Besides, we find that cracks of graphene can be covered by stacking multilayer of graphene and effectively improve the device performance such as shunt resistance. Our best cell with tri-layer HBC-6ImBr and tri-layer graphene has reached 7.1% of power conversion efficiency and a fill factor of around 52%. At last, we try to replace Ag with sliver nano-wire (Ag-NW) to fabricate transparent devices in inverted structure with appropriate annealing temperature.