Research On The Perovskite Solar Cells Based On Indium Sulfide And Doped Titania Electron Transport Layers

Organic–inorganic hybrid perovskite solar cells?PSCs?are kind of third generation solar cell,have been investigated enthusiastically in the past two decades due to their excellent optical and electronic properties,facile preparation process and low cost.In a typical PSCs,electron transport layer?ETL?is a vital component,which extracts photo-generated electrons from the perovskite layer,transports electrons to the electrode,and blocks holes simultaneously.In another word,ETL plays an important role in the process of facilitating electron transport and inhibiting the recombination of photo-generatrd carriers.In this thesis,we put our effort to the ETL of PSCs,including doping of traditional titanium dioxide?Ti O₂?ETL,choosing a new suitable ETL material,discussing the mechanism of improving the performance of electron transport layer and so on.The main research contents are summed up as follows:First,used hydro-thermal synthesis to achieve rare-earth europium ions(Eu³⁺)doping Ti O₂,fabricated PSCs base on Eu-doping mesoporous Ti O₂ as ETL,achieving a power conversion efficiency?PCE?enhancement of 12.90%,the PCE is as high as 17.90%.The Eu-doping improve the quantities of free electrons in the Ti O₂ and thus the conductivity and result in low series resistance.The Fermi level of Eu-doping Ti O₂ shift upward,case a facilitating of electron transport and inhibiting of recombination of photo-generatrd carriers.Second,to further explore the doping effect in Ti O₂ ETL,facilitate electron transport of Ti O₂ ETL,we doped divalent transition mental element ion zinc(Zn²⁺)in to Ti O₂ ETL.In the research,we demonstrate the Zn²⁺-doping Ti O₂ETL has excellent performance to improve short circuit current density and fill factor duo to improve electrical conductivity and decrease of the recombine between electron and hole.Perovskite solar cell fabricated based on Zn-doped Ti O₂ ETL with a power conversion efficiency of 19.69%,which is an increase by 21.62%compared with that of the device based on pure Ti O₂ as ETL.Finally,we synthesized indium sulfide?In₂S₃?nanosheets by solvent-thermal method,and further fabricated PSCs,the solar cells had been well behaved.Compare to Ti O₂ ETL,In₂S₃ ETL exhibits high carrier mobility(above 17.6 cm²V^-1S^-1),energy level is more matched to perovskite,which improve the collection and transportation of electron,thus improve the performance of the solar cells.The PCE of the best device fabricated base on In₂S₃ ETL is 18.83%.Meanwhile,In₂S₃ shows a pretty low annealed temperature during preparation process of the ETL,saving costs and provides a new way to fabricate PSCs based on soft materials.