Application Of Noble Metal Nanorod Aqueous Solution In Planar Perovskite Photovoltaic Devices

Solar cells,as a renewable green energy,play an extremely important role in solving environmental pollution and fossil energy shortage,so they are favored by scientists all over the world.In recent years,organic-inorganic halide perovskite solar cells have developed rapidly.It took less than ten years to increase the photoelectric conversion efficiency from 3.8%to 24.2%.In the structure of perovskite photovoltaic devices,perovskite layer is the most critical functional layer of the whole device.It not only acts as the optical absorption layer,but also plays an effective role in transmitting and separating electrons and holes.Therefore,the quality of perovskite film has a vital impact on the performance of perovskite photovoltaic devices,and the quality of perovskite films can be improved by promoting perovskite crystallization and reducing defects.This paper focuses on the modification of perovskite layer,involving the adjustment of three cationic mixed perovskite components and the doping of silver nanorods and gold nanorods to optimize the performance of devices.The mechanism of improving the performance of devices by aqueous solution and noble metal nanorods is also discussed.The device structure used in this paper is planar structure,and the triple-cation halide perovskite?CsFAMAPbI₃Br₃?is chosen as the optical absorption layer.Firstly,the preparation technology of perovskite basic devices was optimized.The effects of different electron transport layers on the performance of perovskite solar devices were studied by comparing single SnO₂ and double TiO₂-SnO₂ as electronic transport layers.The results show that the energy levels of the double electron transport layer match the perovskite layer better,and the perovskite film deposited on the double electron transport layer is more uniform and compact,which improves the performance and stability of the device and reduces hysteresis.The effects of perovskite layers with two different components prepared under different process conditions on device performance were further studied.The results show that the perovskite films with better quality can be obtained by using 4000 rpm spin coating component as Cs_0.05?FAPbI3?_0.85?MAPbBr₃?_0.15 perovskite material and annealing for 80 minutes,the photoelectric conversion efficiency of the devices can be increased to 18.51%.In order to further improve the performance of the device,Based on the above optimal devices,the effects of adding silver nanorods and gold nanorods to perovskite precursor solution on triple-cation mixed perovskite photovoltaic devices were systematicaly studied,and the optimum doping volume ratio was explored.The results show that the photoelectric conversion efficiency of the devices with 2 vol%silver nanorod aqueous solution and gold nanorod aqueous solution increases to20.29%and 19.46%,respectively.The short-circuit current reaches 22.18 mA/cm²and 21.6 mA/cm²,respectively.At the same time,the fill factor exceeds 82%,which is one of the highest values obtained by triple-cation perovskite solar cells.The main reason is that the interaction of electrons and photons on the surface of noble metal nanorods produces localized suface plasmon resonance effect,which enhances the absorption and scattering of light,increases the capture of light by perovskite layer,reduces the binding energy of excitons,promotes the separation of carriers.Moreover,metal nanorods can form Schottky barriers with perovskite to inhibit carrier recombination,and ultimately optimize the device performance.The presence of an appropriate amount of water is helpful to promote the crystallization of perovskite and to form a more compact and uniform film without pinholes.The synergistic effect of precious metal nanorods and water on the perovskite film has significantly improved the photoelectric conversion efficiency and long-term stability of the devices,which provides a new idea for further optimizing the performance of perovskite photovoltaic devices in the future.