| Energy is the foundation for the development and progress of human society.Since the beginning of the 21 st century,with the continuous consumption and depletion of global fossil energy,global environmental problems have become increasingly serious.Mankind urgently needs to find a renewable new energy to replace traditional fossils.Energy,and solar energy has been valued by researchers for its inexhaustible,inexhaustible,and environmental protection features.Solar cells,which use the photovoltaic effect as a working principle,can directly convert solar energy into electrical energy used in industry and life.It is one of the most promising technologies to solve the human energy crisis.As a new type of photovoltaic device,perovskite solar cells(PSCs)have developed rapidly in recent years.Compared with traditional solar cells,perovskite solar cells have simpler manufacturing processes and lower costs.The high-efficiency theoretical photoelectric conversion efficiency has become the hottest research area in recent years.Although the photoelectric conversion efficiency of the current perovskite solar cells has reached an astonishing 25.2%,there are still a series of problems,such as poor stability.In essence,the main factors that limit the efficiency and stability of photoelectric conversion of PSCs are charge transport and interface charge transfer behavior.Therefore,improving the interfacecharge transfer behavior and lattice matching between perovskite film and titanium dioxide film is to improve the efficiency of PSCs And the main method of stability.This thesis starts with designing,modifying titanium dioxide(Ti O2),optimizing perovskite thin films,and optimizing the perovskite/Ti O2 interface.It uses steady-state fluorescence(PL),transient fluorescence(TRPL),and monochrome photo-electric conversion efficiency(IPCE)And other means to systematically characterize its electrochemical performance.The specific research work and conclusions are as follows:(1)The method of optimizing the crystal structure of the mesoporous Ti O2 and exposing the crystal plane is used to change the interface charge transfer capability of the PSCs to improve the photoelectric conversion efficiency of the PSCs.Using triethylamine and tetrabutyl titanate as the main raw materials,a one-step hydroheat method is used to synthesize pure tetragonal anatase Ti O2 nanoparticles.Compared with the commercial Dyesol-18-NRT,it improves the perovskite solar cells.effectiveness.The self-made Ti O2 was applied to the mesoporous layer of PSCs,and the photoelectric conversion efficiency of the battery obtained after firing at 500 °C for 30 minutes was relatively high,reaching 20.02%,while the commercial Dyesol-18-NRT was only 17.42%,and calcium titanium The charge transfer performance at the ore / Ti O2 interface is significantly enhanced.(2)The one-step anti-solvent method is used to prepare the perovskite film to improve the quality of the perovskite film.Formazan iodate(FAI),methylamine bromide(MABr),lead iodide(Pb I2),and lead bromide(Pb Br2)are the main raw materials.They are dissolved in N-N dimethylformamide(DMF),In methyl sulfoxide(DMSO),a perovskite film is prepared under certain conditions to increase the open circuit voltage of a perovskite solar cell.Compared with the two-step method,the open-circuit voltage of the perovskite film is increased from 0.98 V to1.17 V.(3)An anatase Ti O2 nanoparticle was synthesized by one-step hydrothermal method using niobium pentachloride pentahydrate(Nb Cl5 · 5H2O),tetrabutyl titanate,and acetic acid as main raw materials.The surface was dedoped at 500 ° C.And use it as a mesoporous layer of perovskite solar cells to improve the interfacial charge transfer ability.Compared with the undoped anatase Ti O2 nanoparticles,the efficiency is increased from 20.03 % to 21.07 %(4)For Nb-Ti O2,surface de-doping can expand the lattice of Ti O2 and increase the contact between the perovskite film and the mesoporous Ti O2 film,thereby improving the UV stability of the mesoscopic perovskite solar cells.And thermal stability.After 100 h thermal stability test at 80 ℃,the efficiency of PSCs with de-Nb-Ti O2 as mesoporous layer is only 50% at the beginning,and PSCs with de-Nb-Ti O2 as mesoporous layer The efficiency is 81 % at the beginning,and heat stability has been greatly improved.Under the irradiation of 375 nm UV light(about ~60-suns),after 250 min,the efficiency of PSCs with de-Nb-Ti O2 as mesoporous layer is only 20 % at the beginning,and de-Nb-Ti O2 as mesoporous layer The efficiency of PSCs is 70 % at the beginning,and its UV stability is greatly improved. |
