The Study On The Effect Of Perovskite Solar Cell Performance By Using PCBM:TIPD And In?tu?₃Cl₃ Materials

With the continuous shortage of fossil energy and increasingly serious environmental pollution,human beings urgently need to develop and use clean renewable energy.At present,perovskite solar cells have become a new favorite in the field of renewable energy research,mainly because perovskite materials have higher carrier mobility,longer carrier diffusion length,higher light absorption coefficient,a simple manufacturing process,low cost,and other advantages,but the most common perovskite film in perovskite solar cells is still polycrystalline film,in which there are a lot of defects at grain boundaries and interfaces.The existence of these defects will lead to a decrease in the quality of the perovskite film and further affect the separation and transport of carriers.From the perspective of increasing the quality of the perovskite film and passivating perovskite crystal defects,this thesis adopts [6,6]-phenyl C61 butyric acid methyl ester?PCBM?:acetylacetone titanium?TIPD?and In?SCN2H4?₃C_l3?In?tu?₃C_l3?improve the performance of perovskite solar cells.The specific research contents are as follows.?1?To improve the performance of perovskite solar cells based on PEDOT:PSSPH1000 hole transport material,we used a combination of anti-solvent treatment and defect-state passivation to dissolve PCBM and TIPD in chlorobenzene solution to form a new anti-solvent,which replaces the conventional chlorobenzene anti-solvent and is used to induce the growth of the perovskite film.The efficiency of the prepared ITO/PEDOT:PSSPH1000/Al₂O₃/CH₃NH₃ PbI₃/PCBM/Ag inverted mesoporous structure perovskite solar cell is 15.2%,which is 45% higher than that?10.5%?of the cell prepared with pure chlorobenzene solution.In order to fully understand the reasons for the improved performance,a series of characterization measurements are performed.From the field emission scanning electron microscope and ultraviolet-visible absorption spectrum,it was found that when PCBM:TIPD blended chlorobenzene solution was used to prepare perovskite film,PCBM:TIPD blended film filled the gap between perovskite crystals,which effectively improved the compactness and flatness of the perovskite film and enhanced the light absorption.Conductive atomic force microscopy results showed that the perovskite film treated with PCBM:TIPD based chlorobenzene solution has a larger and evenly distribution surface photocurrent.Fluorescence spectroscopy results showed that the fluorescence intensity of the perovskite film treated with the PCBM:TIPD is quenched,which indicates that the photogeneration electrons can be more effectively transferred to the PCBM:TIPD film from the CH₃NH₃ PbI₃ film.Through the space-limited current measurements,it was found that the defect state density of the device based on the perovskite films with PCBM:TIPD treatment can be reduced to one-third of that of the device without PCBM:TIPD treatment.From the first-principles calculation results,it can be found that electrostatic interaction exists between the oxygen atoms of TIPD and the Pb atoms of the perovskite,which indicates that the TIPD can passivate the defect of CH₃NH₃ PbI₃ at the CH₃NH₃ PbI₃/TIPD interface and enhance the device stability.Moreover,the TIPD induced a interfacial electric field at the CH₃NH₃ PbI₃/TIPD interface,which promotes the electron transfer from the perovskite to the PCBM layer.Therefore,the efficiency and stability of the cells treated with PCBM:TIPD blended chlorobenzene solution have been significantly improved compared with the cells without the PCBM:TIPD,which are mainly attributed to that the TIPD effectively passivated the defects in perovskite film and improved the charge transfer.?2?To improve the performance of inverted ITO/PTAA/CH₃NH₃ PbI₃/PCBM/BCP/Ag perovskite solar cell,we proposed a method to prepare Al₂O₃ mesoporous layer on the hole transport layer PTAA,and to add the In?tu?₃C_l3 into the mesoporous layer.The results show that In?tu?₃C_l3 can increase the size of perovskite crystals and the light absorption intensity of perovskite films;Moreover,In?tu?₃C_l3 can effectively passivate the defects in perovskite crystal crystals,promote the rapid transfer of the holes in the perovskite layer to the hole transport layer,thus reducing the recombination of carriers and increasing the short-circuit current density of the cell.The efficiency of ITO/PTAA/Al₂O₃:In?tu?₃C_l3/CH₃NH₃ PbI₃/ PCBM/BCP/Ag inverted perovskite solar cells was increased from 17.30% to 19.10% compared with the cells without In?tu?₃C_l3.?3?To improve the efficiency and stability of the FTO/cp-TiO₂/mp-TiO₂/CH₃NH₃ PbI₃/ Spiro-OMe TAD/Au perovskite solar cell,the In?tu?₃C_l3 was incorporated into the CH₃NH₃ PbI₃ film for the preparation of FTO/cp-TiO₂/mp-TiO₂/CH₃NH₃ PbI₃:In?tu?₃C_l3/Spiro-OMe TAD/Au perovskite solar cell.The results showed that,compared with the pristine CH₃NH₃ PbI₃ film before the incorporation of In?tu?₃C_l3,the average size of perovskite crystals in the CH₃NH₃ PbI₃:In?tu?₃C_l3 film is increased to about 500 nm from 200 nm,which indicates that the crystallinity of Perovskite thin films is obviously improved by In?tu?₃C_l3.At the same time,the increase of perovskite crystals makes the grain boundary of CH₃NH₃ PbI₃:In?tu?₃C_l3 film decrease,which will effectively reduce the defect density of state of perovskite,thus suppressing the charge recombination.In addition,the incorporated In?tu?₃C_l3 increases the photogenerated voltage on the surface of CH₃NH₃ PbI₃:In?tu?₃C_l3 films,which indicates that In?tu?₃C_l3 makes the separation of photogenerated carriers more effective,which further proves that In?tu?₃C_l3 inhibits the charge recombination in the perovskite active layer.The incorporation of In?tu?₃C_l3 the efficiency of the cell increased from 16.30% to 18.54%.Moreover,due to the defect passivation effect of In?tu?₃C_l3,the cell without encapsulation can still maintain 95% of its initial efficiency after 300 hours in the atmosphere with humidity of 55% and thus the stability has been significantly improved.