Research On Microscopic Photoelectric Properties Of Haloid Perovskite Films Based On Scanning Probe

Perovskite solar cells(PSCs)is a new type of photovoltaic device that has developed extremely rapidly in recent years.The organic-inorganic halide perovskite materials represented by methylamine lead iodine(MAPbI3)have excellent photoelectric performance.The composition and film-forming quality of the perovskite thin film will directly affect the photoelectric performance.In general,compact and large-grained perovskite films are more conducive to carrier generation and transmission.It reduces non-radiative recombination and energy loss.Finally,the performance of perovskite soalr cells will be improved.This article starts with the fabrication process of perovskite solar cells,finds the appropriate perovskite components and electron/hole transport layers.We explore the better process and want to get better performance.On this basis,we improve the crystalline quality of the perovskite films and fabricate perovskite films with larger grains.Through a series of tests to analyze the various characterization changes of the film,Atomic Force Microscope(AFM)was used to characterize and analyze the electrical characteristics of the micro-region of the perovskite film.So we could further study the difference between the perovskite film before and after optimization.In this paper,the organic-inorganic perovskite films were composed by MA and FA which were used as organic cationic groups,PbI2 and PbBr2 were halides.Then we get mixed halogen perovskite materials.In this paper,we choose the perovskite solar cell with the n-i-p planar heterojunction structure.We promote the crystallization process by adding methylamine chloride(MACl)to the perovskite precursor solution.A series of characterizations of perovskite thin films with different concentration of MACl were measured.We confirm that Cl leaves the perovskite crystals with the annealing process.It hardly remains in the crystal lattice and cannot replace iodine atoms or bromine atoms.This article explores the characterization of the film of mixed halide perovskite MACl,such as ultraviolet visible light absorption(UV),electron microscope(SEM),steady state photoluminescence spectroscopy(steady state PL),transient photoluminescence Spectrum(TRPL)etc.We will analyze the difference caused by the absorbance,morphology,carrier lifetime and defect density of MACl for perovskite films.Further explaining the difference in photovoltaic performance of solar cell devices based on this perovskite thin films.This paper use scanning probe to study the microscopic area of the film and analyzes the influence of MACl on the electrical characteristics of the film at a microscopic scale,especially the difference between the grain boundaries and grains.We try to explain the physical process.For the influencing factors of the surface potential of the thin film,we mainly explore the carrier transport layer material of the thin film,the surface morphology of the thin film,surface passivation treatment,thermal stability and other fators.