The Research Of Anode Interface And Active Layer In Perovskite Solar Cells

As the economy continues to grow in the twenty-first century,global warming and environmental change have led to an increasing demand for energy.As a result,people pay more attention to cleaner and more sustainable energy.Many scientists have made a great deal of effort to utilize sunlight since the last century,because PV technology is a major means to achieve clean and sustainable energy.Photovoltaic technology has evolved through silicon-based solar cells,inorganic solar cells such as GaAs,CdTe and Cu?In,Ga?Se₂,dye-sensitized solar cells and organic solar cells.The high cost of materials for these batteries and the high cost of manufacturing hinder their large-area application.However,their deficiencies in large-scale application may be improved in the near future with the emerging organic-inorganic perovskite solar cells.Compared with the traditional dye-sensitized solar cells and organic solar cells,organic-inorganic perovskite solar cells have exhibited a great advantage in the device efficiency.Laboratory device efficiency of organicinorganic perovskite solar cells has been close to the commercial silicon-based solar cells and some multi-component inorganic solar cells,through further interface and active layer optimization can make device efficiency of organic-inorganic perovskite solar cells continue to rise.The different interfacial materials and the crystal quality of the perovskite layer have great influence in deciding the performance of the organic-inorganic perovskite solar cells.Therefore,this paper firstly adopted the one-step anti-solvent rapid crystallization method for making perovskite layer.Then we achieved successful production of highly efficient organic-inorganic perovskite solar cells with the undoped tetrathiafulvalene derivatives?TTA?as the anode interface layer.Meanwhile,measurement of J-V curve for different scanning direction and rate of devices with TTA inserting shown bare notorious hysteresis.It can be seen that the perovskite grains obtained by one-step anti-solvent rapid crystallization method were relatively small,so we can help the perovskite grains grow up with PbS nanoparticles as nuclei.As each parameter is improved,in particular,the improvement of FF significantly make the final power conversion efficiency been greatly improved.The main research contents are as follows:1.Most of the hole-transporting materials in organic-inorganic perovskite solar cells require P-type dopants to increase their conductivity.By introducing an undoped TTA as a new type of hole-transporting material,we obtained a high efficiency perovskite solar cell with photovoltaic conversion efficiency of 16.7%.And we changed scanning speed and direction to find that the hysteresis of organic-inorganic perovskite solar cells was basically eliminated with the TTA inserting.This part of the work also explained the possibility of using undoped tetrathiafulvalene derivatives as hole-transporting materials for organic-inorganic perovskite solar cells.2.As perovskite grains of the first part of the work with the rapid crystallization method was generally only about 150 nm in size,so these smaller grains would have more grain boundaries and the grain boundary is also recombination center of photogenerated carriers.Therefore,we designed and synthesized PbS nanoparticles which had similar crystal structure for perovskite and used onestep method to help the perovskite grains grow up.The Voc,Jsc,and FF of the organic-inorganic perovskite solar cells with this bulk blend were all higher than the reference devices,resulting in a significant increase in the PCE?13% to 15.4%?.This part of the work described the PbS nanoparticles can be used to help the perovskite grains grow up,thus successfully providing a new method to help the perovskite grains to be more bigger.