Research On Assembly And Performance Optimization Of New Thin-film Solar Cell Devices

Dye-sensitized solar cells(DSSCs)and Perovskite solar cells(PSCs),as the third-generation new thin-film solar cells,have a wide range of raw materials,simple process flow,and flexible control methods.The advantages of high theoretical efficiency have been favored by scientific researchers from all over the world.The rapid development of thin-film solar cells has achieved amazing results.However,the development process is often accompanied by surprises and challenges.Generally,traditional DSSCs use platinum electrode(Pt)as the counter electrode material to prepare battery devices,but due to their limited resources,high price,and easy corrosion by chemical electrolytes,their further commercial development is limited.At present,the highest photoelectric conversion efficiency(PCE)of PSCs has reached25.5%.While improving the performance of battery devices,overcoming the problems of stability and green pollution-free is also one of the important ways to develop commercial solar cells.This paper studies the use of graphene-based nanocomposites as the counter electrode of DSSCs to optimize electrocatalytic performance,thereby improving the photovoltaic characteristics and stability of the device at the same time,it studies the effect of additives containing amino functional groups on different systems of perovskite solar cells.The performance is optimized.The specific researches are as follows:1.The composite material of nano-ferrite(MFe₂O₄,M=Co,Mn)and modified graphene(m Gr)is used as the counter electrode material of DSSCs,and the counter electrode of DSSCs is prepared by the one-step drop coating method.Finally,the vacuum pressure difference method is adopted.Assemble DSSCs devices.Under the same conditions,a series of electrochemical tests were performed on the counter electrode prepared from Co Fe₂O₄@m Gr composite material,Mn Fe₂O₄@m Gr composite material,m Gr composite material,and Pt.Among them,the Co Fe₂O₄@m Gr composite material showed good electrocatalysis.Performance and faster electronic transmission rate.Photovoltaic performance test analysis showed the PCE of DSSCs devices prepared from Co Fe₂O₄@m Gr,Mn Fe₂O₄@m Gr,m Gr and Pt were 7.78%,5.55%,4.2%and 7.15%,respectively.It proves that compared with the traditional Pt electrode,the Co Fe₂O₄@m Gr composite material can be used as a new counter electrode material for DSSCs because of its advantages of low cost,high efficiency and non-polluting products.2.FeNi₃/NiFe₂O₄ nanoparticles with high catalytic performance are used to mix with modified graphene through a mechanical mixing method to prepare Fe Ni₃/Ni Fe₂O₄@m Gr composite material as the counter electrode.The study found that Fe Ni₃/Ni Fe₂O₄ nanoparticles were uniformly dispersed on the surface of the modified graphene substrate.Compared with the m Gr and Pt counter electrodes,the Fe Ni₃/Ni Fe₂O₄@m Gr composite exhibits excellent catalytic performance.The lower charge transfer resistance proves that it has a higher catalytic rate.The PCE of the device constructed by Fe Ni₃/Ni Fe₂O₄@m Gr composite material can reach 12.14%,which is significantly higher than the traditional Pt(8.31%)and m Gr(4.81%).At the same time,the cell device composed of Fe Ni₃/Ni Fe₂O₄@m Gr composite material still maintains the efficiency of the original device at 85%after being stored for 42 days under semi-encapsulated conditions.It is proved that DSSCs devices constructed by Fe Ni₃/Ni Fe₂O₄@m Gr composite materials have good photovoltaic performance and long-term stability,and can effectively replace Pt as a new low-cost,high-efficiency and stable counter electrode.3.A type of CsPbI₂Br inverse perovskite solar cell was prepared in the air with methylamine acetate(MAAc)ion solution as a solvent,and the effect of tranexamic acid as an additive on the perovskite film under different molar additions was studied.The device is prepared in air,which is conducive to the further commercial production of PSCs.A trans-perovskite device structure with PEDOT:PSS as the hole transport layer and PC₆₁BM as the electron transport layer can effectively reduce the annealing temperature of the fabricated device and reduce the operation difficulty of the fabrication process.When 0.5%content of additives is added,the morphology of the perovskite film is effectively improved and the crystallinity of its(002)crystal plane is the strongest.At the same time,compared with molar ratio content of 0%(10.75%),0.2%(11.03%)and 1%(8.63%)device PCE increased to 12.14%,a variety of passivating functional groups interact with the surface of the perovskite film to effectively passivate the defects of the perovskite film,reduces the number of holes,and improves the performance of the device.Therefore,tranexamic acid can be used as an effective additive to provide experimental basis for improving perovskite films with other structures.4.Using semicarbazide hydrochloride as a new additive to optimize the CsSnI₃system perovskite solar cell.The development of lead-free perovskite solar cells is mainly restricted by two aspects:First,the metal cation Sn²⁺is easily oxidized from the divalent state to the tetravalent state,which then changes the crystal structure of the perovskite;secondly,the lower hole formation energy leads to the morphology ofSnvacancies in the crystal lattice produces a large number of holes in the film,which increases the contact probability of the upper and lower transmission layers.In this paper,semicarbazide hydrochloride is used as an additive,and tin ions with insufficient amine bond coordination in semicarbazide hydrochloride are used to passivate dangling bonds and defects,thereby inhibiting the recombination of carriers and improving the performance of PSCs.When 10%of semicarbazide hydrochloride is added,the quality of the film is effectively improved,forming a dense and smooth perovskite film.It is obtained that when the content of the additive is 10%,the device obtains a PCE of 2.89%,which is higher than that of the device without addition and other ratios.It is proved that semicarbazide hydrochloride can be used as an effective additive to improve the film quality of CsSnI₃ solar cells to improve device performance.