| The rapid development of human society is accompanied by the rapid consumption of energy,which leads to the increasing demand for renewable energy.The gradual depletion of traditional energy makes people pay more and more attention to new energy.Organic-inorganic hybrid perovskite solar cells have been widely concerned in the third generation solar cells because of their good raw material abundance,good absorption color gamut,low carrier recombination rate and high carrier mobility.After a long-term exploration and research,the highest photoelectric conversion efficiency of perovskite solar cells has reached an amazing 25.2%.The commonly used device structures include mesoporous structure,formal planar heterostructure and trans(inverted)planar heterostructure.Among them,trans planar heterostructure has been prepared by researchers because it can be prepared in full solution and the preparation process is relatively simple Extensive attention.In this paper,based on the existing structure of trans perovskite solar cells,a series of materials are synthesized and applied to the devices of perovskite solar cells on the premise of low cost and easy repetition.The common problems such as energy level band gap matching and perovskite cell quality are solved.The main work includes the following two aspects:(1)Based on the energy level band gap matching and hole transport layer carrier mobility,the hole transport layer material in the trans perovskite solar cell device is replaced to improve the open circuit voltage and short circuit current of the device.The specific contents include:the selection and synthesis of hole transport layer materials,specifically the synthesis of Ni O_x and Cu O_x and the preparation of their dispersion PEDOT:PSS The replacement of Cu O_x and the addition of Cu O_x as the interface layer work in two steps,and the device efficiency is reduced from12.64%(PEDOT:PSS)Gradually increased to 16.58%(Ni O_x),and finally reached the highest efficiency of 19.91%(Ni O_x/Cu O_x).At the same time,we have a deep research on the devices using Cu O_x as the interface layer.We think that Cu O_x as the interface layer and Ni O_x form a dipole layer,which provides a stronger electric power for carrier transport.The addition of the interface layer also eliminates the energy difference between the hole transport layer and the calcium titanium ore layer,thus improving the overall performance of perovskite solar devices.(2)Non radiative recombination is a major obstacle to the improvement of the performance of perovskite solar cells and one of the reasons for the loss of open circuit voltage.Grain boundary passivation is one of the effective methods to reduce nonradiative recombination,which can effectively reduce cell surface defects and improve the quality of perovskite films.Based on the existing preparation process of perovskite active layer,in order to prepare higher quality perovskite film and obtain higher quality perovskite cell,we try to improve the crystallization process by using additives in the perovskite precursor.Carbon quantum dots were synthesized by using common raw materials(acetone,sodium hydroxide)under laboratory conditions,and used as additives in trans perovskite solar cells.The device efficiency increased from 15.67%to 18.24%,and remained 73.4%of the initial efficiency after 48 hours in air.At the same time,the mechanism of carbon quantum dot additives in the improvement of perovskite active layer was studied in detail. |
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