Researches On Application Of Cerium Oxide In Perovskite Solar Cells Devices

Perovskite solar cells(PSCs),as a new type of solar cell device,have been rapidly developed in recent years.Their power conversion efficiency(PCE)has increased rapidly from initial 3.8%reported in 2009 to the current 25.2%.However,the PCE and long-term stability of the device are two important factors that limit its industrial production.The commonly used cell structure includes FTO,electron transport layer(ETL),mesoporous layer,perovskite layer,hole transport layer(HTL)and metal electrode.The properties of the active layers and the interaction between the interfaces have an impact on the cell performance.The research in this thesis mainly focuses on solving the problems about electron transport materials as well as mesoporous materials commonly used in batteries and fabricating efficient and stable PSCs through chemical analysis and interface modification methods.The thesis consists of five chapters,which are as follows:Chapter 1.Describe the basic principle and development process of PSCs,summarize the main problems and puts forward the research purpose,significance and corresponding ideas.Chapter 2.The electron transport layer of PSCs is modified by cerium oxide(CeOx)to improve the performance and stability of battery.The introduction of CeOx can match the band energy level,promote the transport of photogenerated electrons,and thus improve the PCE of the device.Besides,the stability of PSCs under humidity,heat and ultraviolet light is improved simultaneously.Chapter 3.CeOx is directly used as mesoporous layers to verify the advantages of cerium oxide in devices.In this chapter,CeOx paste is prepared and used to directly assemble battery components instead of commercial TiO2 paste.The high charge mobility,high conductivity and the role of cerium oxide in charge transfer and recombination are proved,which promotes the further application of CeOx in solar cells.Chapter 4.The mesoporous layer of PSCs is modified by CeOx interface layer to further improve the device performance and UV stability.The introduction of CeOx layer can improve the match of band energy level,promote the charge transport and collection in the device,and improve the utilization rate of UV light,thus further improving the device efficiency and UV stability.Chapter 5.Summarize and prospect for this thesis.This paper focuses on the influence of cerium oxide as charge transfer material on the device,and probes into the mechanism of the influence.The introduction of cerium oxide improves the performance of the corresponding batteries,whether applied to electron transport materials or mesoporous layer materials.The research work in this paper provides a new idea for the design of efficient and stable PSCs from the perspective of charge transfer and carrier composition.