Stability Study And Application Of Silver Nanowire Electrode For Perovskite Solar Cells

Despite the outstanding features of high transmittance and low sheet resistance of silver nanowire?AgNW?based flexible transparent electrodes from solution based process,their applications in perovskite solar cells?PVSCs?as bottom electrodes are significantly confined due to the stability issue brought by the corrosion of halogen species from perovskite layer.In this paper,we studied the effects of conventional perovskite precursors and perovskite film on AgNW electrode under single ambient condition,and the strategies to improve the stability of silver nanowire electrode.Here,large size graphene oxides were introduced to protect the bottom AgNW network against corrosion,and the composite electrode of AgNW/LGO had been demonstrated for PVSC yielding power conversion efficiency?PCE?of 9.62%.The main work of this thesis includes:Firstly,the effects of common used perovskite precursors of PbX₂ and MAX?X:Cl or Br or I?and perovskite film of MAPbI₃ on AgNW electrode were respectively investigated under the single ambient condition,including light,oxygen and water.The final composite film is analyed by X-ray diffraction?XRD?.Experimental results indicated that,compared to oxygen and water,PbX₂ had more severe corrosive effect on AgNW electrode under light illumination.The corrosion speed of electrode by PbX₂ is increased with the increase of halogen atomic number of X.Meanwhile,the attack of MAX against AgNW in oxygen and water environment was more severe than the one under light irradiation.In addtion,the decomposition of MAPbI₃ will be accelerated under all the condition of illumination,oxygen and moisture,speeding up the corrosion aganist AgNW electrode.The corrosion rate of AgNW/MAPbI₃ under light illumination was the fastest,followed by moisture and oxygen.Secondly,in order to improve the stability of AgNW electrode,the GO flakes and the cuprous thiocyanate?CuSCN?nanoclusters hade been proposed to be prepared on top of nanowires by steady hot airflow assisted deposition and electrodeposition respectively.However,it is found that the CuSCN nanocluster can not improve the stability of AgNW electrode.A contradictory result had been obtained that the denser coating of the nanocluster on the AgNW surface,the faster the corrosion rate of AgNW electrode has been experienced.Experimental results indicate that the AgNW electrode protected by the film composed by 60?m LGO can maintain the original resistance for more than 45 hours under continuing external bias and light irradiation,and exhibited transmittance of 83.8%and sheet resistance of 38.5?/sq.Finally,the PVSC was fabricated on the composite electrode based on AgNW/LGO.After optimization on the device fabrication,the PVSC using the AgNW/RLGO electrode showed an open circuit voltage(V_OC)of 0.87V,short-circuit current(J_SC)of 15.43mA/cm²,fill factor?FF?of 70.9%,and PCE of 9.62%,which is about 85%of the PCE from the solar cell on commercial ITO.These results clearly demonstrate the potential of AgNW/RLGO composite as bottom electrode for PVSCs.