Peparation Of Carbon Composites And Their Application In Perovskite Solar Cells

As a new type of third-generation solar cells,perovskite solar cells(PSCs)have drawn great attention due to simple preparation technology,low manufacture costs and high power conversion efficiency(PCE).Most of the devices relied on noble metal electrodes(Au,Ag)and require vacuum equipment for fabrication.And need to add spiro-MeOTAD,which is a hole transport material.It is not only expensive but also shows inferior stability.And this will be very unfavorable for PSCs industrialization.Carbon materials are cheap,stable and can be well used for collecting holes.So replac?ing the hole transport layer and the noble metal electrodes with carbon materials is of a very important value.In this thesis,different carbon materials were used as counter electrode and embedded into perovskite layer,and high power conversion efficiencies were obtained.Firstly,PSCs were prepared by using carbon nanotubes,conductive carbon black,conductive carbon,carbon nanofibers,activated carbon,oligegraphene and flake graph-ite as the counter electrode.It was indicated that carbon nanotubes performed best amongst these carbon materials.The stability test to PSCs was conducted,conductive carbon black and conductive carbon as the carbon counter electrode,the efficiency of PSCs remained above 90%of the original after 480h.In addition,we researched the fabrication of composite as carbon counter electrode for PSCs.It was found that using activated carbon alone as counter electrode gave poor performance.When composited with oligegraphene,the cell performance was enhanced and the PCE is 5.94%.Secondly,based on the acrylic binder system,a mixture of flake graphite and con-ductive carbon black were used to produce conductive carbon paste.The counter elec-trode of PSCs was prepared by a simple spraying method.After analysis,when the ratio of flake graphite and conductive carbon black is 1:3,the power conversion efficiency of PSCs was the highest.The PSCs based on flake graphite:carbon black=1:6 electrode exhibited good stability in air:the PCE remained above 80%of original after 3000h.Finally,different concentration of carbon nanotubes and carbon nanofibers were embedded into perovskite layer,and studied the influence on the morphology and prop-erties of perovskite thin film.It was found that the PCE of perovskite solar cells with addition of 0.1 mg/mL carbon nanotubes and carbon nanofibers is higher than that of the pristine perovskite solar cells.And the perovskite films showed larger grain size.The study found that O.lmg/mL carbon nanofibers was embedded into the light absorbing CH3NH3Pb13 perovskite layer and conductive carbon was used as counter electrode,the highest PCE of 10.64%was achieved.