The Study On The Application Of Carbon Materials In The Counter Electrode Of Perovskite Solar Cells

Solar cells have been developed for three generations now day.Compared with the two previous generations,the perovskite solar cells(PSCs)in the third generation of new solar cells are widely concerned by researchers because of the lower cost,simpler process and excellent photoelectric conversion efficiency.However,there are still many problems need solving.For example,most of the materials of hole transport layer of PSCs are traditional organic molecules or polymer,and the materials of counter electrode always be precious metal materials such as gold and silver,which are expensive and do not benefit to the commercialization of PSCs.In addition,the stability of PSCs is poor,which means they are not conducive to preservation.In this paper,the improvement of PSCs was based on the electrode layer and the provskite layer.Firstly,the electrode layer of the PSCs were formed by the materials combined with carbon nanotubes and nano-carbon fibers.According to the J-V test,the photoelectric conversion efficiency of the battery has reached to 12.77%when the carbon nanotubes and nano-carbon fibers were combined at a mass ratio of 3:1.Electrochemical tests have also shown that the electrode has better conductivity and hole transporting ability.Secondly,the carbon nanotube counter electrode layer was treated by a physical vibration to study the impact to the performance of cells with the vibration power and time.As a result,the highest efficiency is 13.53%when the vibration power is 70W and the vibration is 7min.Scanning electron microscope has showed that the vibration can make carbon nanotubes more compact.The electrochemical impedance test and Steady-state PL spectra has also showed that the vibrating counter electrode has better conductivity and hole transporting ability.Finally,in order to enhance the thermal stability of the perovskite layer in the PSCs,FA+,one kind of cationic with large size was used to replace MA+.According to the J-V test,the photoelectric conversion efficiency has reached to 8.53%.The thermal stability has a great improvement compared with MAPb3.