Effect Of Interface Regulation And Additive Engineering On Performance Of Perovskite Solar Cells

Perovskite solar cells stand out in the photovoltaic field due to their adjustable band gap,high absorption coefficient and low exciton binding energy,and become the next generation photovoltaic devices with great potential.In recent years,its photoelectric conversion efficiency（PCE）has been rapidly improved from 3.8%in2009 to a certified value of 25.8%.However,the defects existence of and interface mismatch greatly limit the further improvement of its efficiency.In this paper,experiments and simulation are combined to study the scientific path to improve the efficiency and stability of perovskite solar cells.The device performance is optimized by additive engineering and interface regulation.Its main contents are as follows:（1）In order to regulate the crystallization and passivate the defects of perovskite films,the multi-functional halogen salt（benzotriazo-1-dipyrrolidine-hexafluorophosphase（BDPF₆））was introduced into the perovskite precursor solution using additive engineering strategy.The multifunctional synergistic effect between additive molecules and perovskite is helpful to obtain efficient and stable perovskite solar cells.The results show that that the groups in BDPF₆ can synergize to passivate anionic and cationic defects in the perovskite,effectively inhibit ion migration,improve the crystallinity of the perovskite,and obtain smooth perovskite films.Finally,the multi-functional halogen salt BDPF₆-modified perovskite solar cell showed an efficiency of 22.68%,and the environmental stability of the device was significantly improved.（2）In order to regulate the buried interface,an ordered chemical bridge management strategy based on synergistic functional groups（fluorine F and carboxylic acid C=O）is proposed,and the modification agent of pentafluoropyridine carboxylic acid（5-FPA）is used as the"chemical bridge"of the buried interface.The results show that the introduction of 5-FPA can realize the bilateral synergistic passivation of the buried interface and the ordered arrangement of molecules,which is beneficial to the extraction and transmission of photogenerated charge carriers and the stability of crystal structure.In addition,the introduction of F appropriately increases the hydrophobicity of the electron transport layer,which is conducive to inhibiting heterogeneous nucleation,thus facilitating perovskite crystallization.Finally,the 5-FPA modified device obtained 22.82%efficiency and showed high stability.After optimization,the device efficiency is increased to 23.14%.（3）The iteration efficiency of device design and verification can be effectively improved by building physical models and carrying out device structure simulation.In this paper,the Optical–Electrical–Thermal simulation of perovskite solar cells is carried out by SCAPS-1D simulation tool.Firstly,MAPb I₃/MASn I₃ was used as the perovskite absorption layer to study the performance of tandem perovskite solar cells.The results show that the MAPb I₃/MASn I₃ tandem perovskite structure can achieve the maximum utilization of light and better energy level matching,which is beneficial to the extraction and transport of photogenerated charge carriers.Finally,the device based on tandem perovskite structure achieved an efficiency of 30.05%.In this paper,the experimental research is carried out from two aspects of additive engineering and buried interface regulation.The strategy adopted is helpful to explore the passivation mechanism and carrier dynamics behavior,and can be used as a reference for the performance improvement of perovskite solar cells.In addition,the photoelectric-thermal simulation of the tandem structure perovskite solar cell was carried out through simulation to provide reference for experimental research.