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Two-step Preparation And Performance Optimization Of Full Printable Perovskite Solar Cells

Posted on:2020-03-24Degree:MasterType:Thesis
Country:ChinaCandidate:P F WangFull Text:PDF
GTID:2392330623466747Subject:Materials Science and Engineering
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Since the report of all-solid state perovskite solar cells in 2012,the power conversion efficiency?PCE?has increased from 3.8%to 23.7%in recently years,which is comparable to commercial silicon cells.At present,most of the research used expensive hole transport materials,and the noble metal electrode is prepared by the extremely energy-consuming vacuum evaporation method,which increases the preparation cost of the perovskite solar cell and restricts the subsequent large-scale commercial application.In this paper,a carbon-based perovskite solar cell device with a hole-free transport layer is prepared by screen printing technology,which greatly reduces the manufacturing cost.The FAPbI3-based perovskite devices was prepared by two-step method,and the effect on device performance was further investigated by doping with monovalent cation and halogen anion.The main research contents and results of the thesis are as follows:Firstly,comparing the performance difference between FAPbI3 and MAPbI3perovskite,the UV-Vis test shows that the band gap of MAPbI3 and FAPbI3 are1.55 eV and 1.48 eV,respectively.The FAPbI3 perovskite has better performance of light absorption in the wavelength range of 300-800 nm,therefore,the FAPbI3perovskite device achieved higher photocurrent,and the PCE was increased from7.48%to 10.81%.XRD was used to monitor the change of FAPbI3 perovskite film under different environmental conditions.There was no phase transition occurred in FAPbI3 perovskite film under N2 environment,but it was easy to occurred under 60%relative humidity?RH?environment.Due to the hydrophobic action of the carbon counter electrode layer,the phase transition of FAPbI3 perovskite crystal in the device can slow down.Secondly,the precursor solution was doped with different concentrations of IA group ions?K+,Rb+,Cs+?to investigate its effect on the FAPbI3-based perovskite.It is found that the doping of K+,Rb+and Cs+ions can improve the crystallization of FAPbI3 perovskite.While Rb+and Cs+ions can effectively inhibit the phase transition of FAPbI3 perovskite,but K+ions have no effect on inhibiting phase transition.The J-V test results show that the PCE of the device is significantly improved compared with the control device?10.81%?after doping with 10%Cs ions,and the optimal PCE reaches 11.71%.The optimum PCE of the device after doping 1%K and 1%Rb was10.68%and 11.55%respectively.Under humidity,temperature and light stability tests,it was found that both K+and Cs+ion doping can improve the stability of the device under three test conditions,and the improvement effect after Cs+doping is more obvious.After Rb+ion doping,the stability of the device under humidity environment is not improve.Thirdly,the effect on the FAPbI3-based perovskite was investigated after doping halogen anion Br-in the precursor solution.It was found by XRD that no characteristic peak of yellow phase?-FAPbI3 after Br-doping,indicating that the introduction of Br-ion can inhibit phase transition of.In the J-V test,the device had an optimum PCE of 11.53%when doped with 10%Br concentration.However,the phase transition of FAPbI3 perovskite still occurred in long-term storage.In order to further improve the PCE and stability of the device,10%Br-Cs was doped in the precursor solution,and the champion device has a PCE of 14.14%was prepared by continuously optimizing preparation process.In the long-term stability test,it was found that the 10%Br-Cs devices unencapsulated still had an initial PCE of 87.0%for 120 days under amient environmment.After encapsulation,the 10%Br-Cs devices were tested by thermal cycling and found that there was still 102%of initial PCE after 100 cycles.It is demonstrated that the 10%Br-Cs device has excellent thermal stability.
Keywords/Search Tags:Perovskite solar cells, Screen printing, Two-step method, Element doping, Stability
PDF Full Text Request
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