| In recent years,organic-inorganic hybrid perovskite solar cells(PSCs)have developed rapidly,mainly due to the excellent photoelectric performance of organic-inorganic hybrid perovskite materials.In just a few years,its photoelectric conversion efficiency(PCE)has reached 25.2%now,far higher than 3.8%in 2009.PSCs are usually with a layered structure,which is composed of FTO conductive glass,electron transport layer,perovskite layer,hole transport layer,and metal electrode.The electron transport layer plays a very important role in PSCs,which mainly used to transport electrons and prevent current loss caused by recombination of electrons and holes.Although TiO2 was initially used as the electron transport layer,ZnO is found with higher electron mobility and light transmittance than TiO2.Therefore ZnO has received widespread attention from scientists.The PSCs based on ZnO electronic transportation layer were prepared and studied in this thesis.SEM,AFM,PL are applied to characterize the PSCs and the photoelectric performance of the PSCs under different experimental conditions are tested.The main experimental contents and results are as follows:(1)The ZnO thin film was prepared by the sol-gel method and it was used as the electron transport layer of PSCs.The effects of the preparation process of the ZnO thin film and annealing temperature of the perovskite layer on the performance of PSCs were studied.First,different concentrations of ZnO precursor solutions were prepared to explore the effect of different concentrations of ZnO solutions on the performance of PSCs.Then,ZnO films with different thickness were prepared by changing the times of spin coating to research the influence of the thickness of the ZnO film on the performance of PSCs.Finally,the effect of different annealing temperatures on the performance of PSCs was studied by adjusting the annealing temperature of perovskite to obtain the optimal preparation process of ZnO-based PSCs.Based on experimental data,when the concentration of ZnO solution and the annealing temperature of the perovskite layer are 0.6 mol/L and 70℃,respectively,the thickness of the prepared ZnO film is about 80nm-90nm and the corresponding PSCs show the optimum PCE of 6.92%.(2)The effect of surface modification or doping of ZnO film on the performance of PSCs was studied.Ammonia water steam heat treatment on the ZnO film.CTAB and MgO coating for interfacial modification of the ZnO are studied.The amount of ammonia water and the time of steaming ammonia water treatment are studied.When the amount of ammonia water and the time of steaming ammonia treatment are 100 uL and 30 min,respectively,the performance of the PSCs is the best,showing a high PCE of 10.26%.The concentration of CTAB and the annealing temperature of the perovskite layer after CTAB modification were studied.It is concluded that when the CTAB concentration and the annealing temperature are 0.01 mol/L and 70℃,respectively,the PSCs performance is the best,showing a PCE of 10.11%.The concentration of the MgO solution and the annealing temperature of the modified perovskite layer were also studied.Results show that when the MgO concentration and the annealing temperature are 0.1 mol/L and 70℃,respectively,the performance of the is the best,with the PCE of 12.04%.(3)The effect of the structure of the composite double electron transport layer on the performance of PSCs was studied.The combination of SnO2,TiO2 with ZnO were used to prepare ZnO/TiO2,ZnO/SnO2 composite double electron transport layer structure,respectively.The thickness of the films were regulatedby changing the times of spin coating.For ZnO/TiO2 system,ZnO(1)/TiO2(1)and ZnO(2)/TiO2(1)were researched,and the PSCs performance based on ZnO(1)/TiO2(1)electron transport layer was the best,showing a high PCE of 11.83%.For ZnO/SnO2 system,ZnO(1)/SnO2(1)and ZnO(2)/SnO2(1)were researched and the PSCs performance based on ZnO(1)/SnO2(1)electron transport layer was the best,showing a high PCE of 11.33%. |
PDF Full Text Request